Novell SUSE Linux Enterprise 10 Storage Administration Guide
Storage Administration Guide
Novell®
SUSE® Linux Enterprise Server
novdocx (en) 13 May 2009
AUTHORIZED DOCUMENTATION
10 SP2
May 15, 2009
www.novell.com
SLES 10 SP2: Storage Administration Guide
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novdocx (en) 13 May 2009
novdocx (en) 13 May 2009
4 SLES 10 SP2: Storage Administration Guide
Contents
About This Guide 9
1 Overview of EVMS 11
1.1 Benefits of EVMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.2 Plug-In Layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.3 Supported File Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.4 Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.5 Location of Device Nodes for EVMS Storage Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2 Using EVMS to Manage Devices 15
2.1 Configuring the System Device at Install to Use EVMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.1.1 Before the Install . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.1.2 During the Server Install . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.1.3 After the Server Install . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.2 Configuring an Existing System Device to Use EVMS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.2.1 Disable the boot.lvm and boot.md Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.2.2 Enable the boot.evms Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.2.3 Edit the /etc/fstab File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.2.4 Edit the Boot Loader File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.2.5 Force the RAM Disk to Recognize the Root Partition . . . . . . . . . . . . . . . . . . . . . . . . 25
2.2.6 Restart the Server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.2.7 Verify that EVMS Manages the Boot, Swap, and Root Partitions . . . . . . . . . . . . . . . 26
2.3 Configuring LVM Devices to Use EVMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.4 Using EVMS with iSCSI Volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.5 Using the ELILO Loader Files (IA-64) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
2.6 Starting EVMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
2.7 Starting the EVMS Management Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
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3 Using UUIDs to Mount Devices 31
3.1 Naming Devices with udev. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.2 Understanding UUIDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.2.1 Using UUIDs to Assemble or Activate File System Devices . . . . . . . . . . . . . . . . . . . 32
3.2.2 Finding the UUID for a File System Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.3 Using UUIDs in the Boot Loader and /etc/fstab File (x86) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.4 Using UUIDs in the Boot Loader and /etc/fstab File (IA64) . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3.5 Additional Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4 Managing EVMS Devices 35
4.1 Understanding Disk Segmentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.1.1 Segment Managers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.1.2 Disk Segments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
4.2 Initializing Disks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
4.2.1 Before You Begin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
4.2.2 Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4.2.3 Adding a Segment Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4.3 Removing the Segment Manager from a Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Contents 5
4.4 Creating Disk Segments (or Partitions) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
4.5 Configuring Mount Options for Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4.6 What’s Next . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
5 Managing Multipath I/O for Devices 43
5.1 Understanding Multipathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
5.1.1 What Is Multipathing? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
5.1.2 Benefits of Multipathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
5.2 Planning for Multipathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
5.2.1 Guidelines for Multipathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
5.2.2 Using Multipathed Devices Directly or in EVMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
5.2.3 Using LVM2 on Multipath Devices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
5.2.4 Using mdadm with Multipath Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
5.2.5 Partitioning Multipath Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
5.2.6 Supported Architectures for Multipath I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
5.2.7 Supported Storage Arrays for Multipathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
5.3 Multipath Management Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
5.3.1 Device Mapper Multipath Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
5.3.2 Multipath I/O Management Tools. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
5.3.3 Using mdadm for Multipathed Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
5.3.4 The Linux multipath(8) Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
5.4 Configuring the System for Multipathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
5.4.1 Preparing SAN Devices for Multipathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
5.4.2 Partitioning Multipathed Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
5.4.3 Configuring the Server for Multipathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
5.4.4 Adding multipathd to the Boot Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.4.5 Creating and Configuring the /etc/multipath.conf File . . . . . . . . . . . . . . . . . . . . . . . . 55
5.5 Enabling and Starting Multipath I/O Services. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
5.6 Configuring Path Failover Policies and Priorities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
5.6.1 Configuring the Path Failover Policies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
5.6.2 Configuring Failover Priorities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
5.6.3 Using a Script to Set Path Priorities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
5.6.4 Configuring ALUA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
5.6.5 Reporting Target Path Groups. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.7 Tuning the Failover for Specific Host Bus Adapters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.8 Configuring Multipath I/O for the Root Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.9 Configuring Multipath I/O for an Existing Software RAID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
5.10 Scanning for New Devices without Rebooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
5.11 Scanning for New Partitioned Devices without Rebooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
5.12 Viewing Multipath I/O Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
5.13 Managing I/O in Error Situations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
5.14 Resolving Stalled I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
5.15 Additional Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
5.16 What’s Next . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
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6 Managing Software RAIDs with EVMS 75
6.1 Understanding Software RAIDs on Linux. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
6.1.1 What Is a Software RAID?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
6.1.2 Overview of RAID Levels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
6.1.3 Comparison of RAID Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
6.1.4 Comparison of Disk Fault Tolerance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
6.1.5 Configuration Options for RAIDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
6.1.6 Interoperability Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
6 SLES 10 SP2: Storage Administration Guide
6.1.7 Guidelines for Component Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
6.1.8 RAID 5 Algorithms for Distributing Stripes and Parity . . . . . . . . . . . . . . . . . . . . . . . . 80
6.1.9 Multi-Disk Plug-In for EVMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
6.1.10 Device Mapper Plug-In for EVMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
6.2 Creating and Configuring a Software RAID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
6.3 Expanding a RAID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
6.3.1 Adding Mirrors to a RAID 1 Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
6.3.2 Adding Segments to a RAID 4 or 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
6.4 Adding or Removing a Spare Disk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
6.4.1 Do You Need a Spare Disk? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
6.4.2 Adding a Spare Disk When You Create the RAID. . . . . . . . . . . . . . . . . . . . . . . . . . . 87
6.4.3 Adding a Spare Disk to an Existing RAID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
6.4.4 Removing a Spare Disk from a RAID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
6.5 Managing Disk Failure and RAID Recovery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
6.5.1 Understanding the Disk Failure and RAID Recovery . . . . . . . . . . . . . . . . . . . . . . . . . 87
6.5.2 Identifying the Failed Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
6.5.3 Replacing a Failed Device with a Spare . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
6.5.4 Removing the Failed Disk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
6.6 Monitoring Status for a RAID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
6.6.1 Monitoring Status with EVMSGUI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
6.6.2 Monitoring Status with /proc/mdstat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
6.6.3 Monitoring Status with mdadm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
6.6.4 Monitoring a Remirror or Reconstruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
6.6.5 Configuring mdadm to Send an E-Mail Alert for RAID Events. . . . . . . . . . . . . . . . . . 93
6.7 Deleting a Software RAID and Its Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
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7 Managing Software RAIDs 6 and 10 with mdadm 97
7.1 Creating a RAID 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
7.1.1 Understanding RAID 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
7.1.2 Creating a RAID 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
7.2 Creating Nested RAID 10 Devices with mdadm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
7.2.1 Understanding Nested RAID Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
7.2.2 Creating Nested RAID 10 (1+0) with mdadm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
7.2.3 Creating Nested RAID 10 (0+1) with mdadm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
7.3 Creating a Complex RAID 10 with mdadm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
7.3.1 Understanding the mdadm RAID10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
7.3.2 Creating a RAID10 with mdadm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
7.4 Creating a Degraded RAID Array. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
8 Resizing Software RAID Arrays with mdadm 107
8.1 Understanding the Resizing Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
8.1.1 Guidelines for Resizing a Software RAID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
8.1.2 Overview of Tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
8.2 Increasing the Size of a Software RAID. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
8.2.1 Increasing the Size of Component Partitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
8.2.2 Increasing the Size of the RAID Array . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
8.2.3 Increasing the Size of the File System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
8.3 Decreasing the Size of a Software RAID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
8.3.1 Decreasing the Size of the File System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
8.3.2 Decreasing the Size of Component Partitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
8.3.3 Decreasing the Size of the RAID Array . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Contents 7
9 Installing and Managing DRBD Services 117
9.1 Understanding DRBD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
9.2 Installing DRBD Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
9.3 Configuring the DRBD Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
9.4 Testing the DRBD Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
9.5 Troubleshooting DRBD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
9.5.1 Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
9.5.2 Host Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
9.5.3 TCP Port 7788 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
9.5.4 The --do-what-i-say Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
9.6 Additional Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
10 Troubleshooting Storage Issues 123
10.1 Is DM-MP Available for the Boot Partition? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
10.2 Rescue System Cannot Find Devices That Are Managed by EVMS . . . . . . . . . . . . . . . . . . . 123
10.3 Volumes on EVMS Devices Do Not Appear After Reboot . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
10.4 Volumes on EVMS Devices Do Not Appear When Using iSCSI . . . . . . . . . . . . . . . . . . . . . . 124
10.5 Device Nodes Are Not Automatically Re-Created on Restart . . . . . . . . . . . . . . . . . . . . . . . . 124
novdocx (en) 13 May 2009
A Documentation Updates 125
A.1 May 15, 2009 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
A.1.1 Managing Multipath I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
A.2 November 24, 2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
A.2.1 Managing Multipath I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
A.2.2 Using UUIDs to Mount Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
A.3 June 10, 2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
A.3.1 Managing Multipath I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
A.4 March 20, 2008 (SLES 10 SP2). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
A.4.1 Managing Multipath I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
8 SLES 10 SP2: Storage Administration Guide
About This Guide
This guide provides information about how to manage storage devices on a SUSE® Linux
Enterprise Server 10 Support Pack 2 server with an emphasis on using the Enterprise Volume
Management System (EVMS) 2.5.5 or later to manage devices. Related storage administration
issues are also covered as noted below.
Chapter 1, “Overview of EVMS,” on page 11
Chapter 2, “Using EVMS to Manage Devices,” on page 15
Chapter 3, “Using UUIDs to Mount Devices,” on page 31
Chapter 4, “Managing EVMS Devices,” on page 35
Chapter 5, “Managing Multipath I/O for Devices,” on page 43
Chapter 6, “Managing Software RAIDs with EVMS,” on page 75
Chapter 7, “Managing Software RAIDs 6 and 10 with mdadm,” on page 97
Chapter 8, “Resizing Software RAID Arrays with mdadm,” on page 107
novdocx (en) 13 May 2009
Chapter 9, “Installing and Managing DRBD Services,” on page 117
Chapter 10, “Troubleshooting Storage Issues,” on page 123
Audience
This guide is intended for system administrators.
Feedback
We want to hear your comments and suggestions about this manual and the other documentation
included with this product. Please use the User Comments feature at the bottom of each page of the
online documentation, or go to www.novell.com/documentation/feedback.html and enter your
comments there.
Documentation Updates
For the most recent version of the SUSE Linux Enterprise Server 10 Storage Administration Guide
for EVMS, visit the Novell Documentation Web site for SUSE Linux Enterprise Server 10 (http://
www.novell.com/documentation/sles10).
Additional Documentation
For information about managing storage with the Linux Volume Manager (LVM), see the SUSE
Linux Enterprise Server 10 Installation and Administration Guide (http://www.novell.com/
documentation/sles10).
For information about iSNS (Internet Storage Name Service), see “iSNS” (http://www.novell.com/
documentation/sles10/sles_admin/index.html?page=/documentation/sles10/sles_admin/data/
cha_isns.html) in the SUSE Linux Enterprise Server 10 Installation and Administration Guide (http:/
/www.novell.com/documentation/sles10).
About This Guide 9
Documentation Conventions
In Novell documentation, a greater-than symbol (>) is used to separate actions within a step and
items in a cross-reference path.
®
A trademark symbol (
, TM, etc.) denotes a Novell trademark. An asterisk (*) denotes a third-party
trademark.
novdocx (en) 13 May 2009
10 SLES 10 SP2: Storage Administration Guide
1
Overview of EVMS
The Enterprise Volume Management System (EVMS) 2.5.5 management tool for Linux* is an
extensible storage management tool that integrates all aspects of volume management, such as disk
partitioning, the Logical Volume Manager (LVM), the Multiple-Disk (MD) manager for software
RAIDs, the Device Mapper (DM) for multipath I/O configuration, and file system operations.
Section 1.1, “Benefits of EVMS,” on page 11
Section 1.2, “Plug-In Layers,” on page 11
Section 1.3, “Supported File Systems,” on page 12
Section 1.4, “Terminology,” on page 12
Section 1.5, “Location of Device Nodes for EVMS Storage Objects,” on page 13
1.1 Benefits of EVMS
novdocx (en) 13 May 2009
1
EVMS provides the following benefits:
An open source volume manager
A plug-in framework for flexible extensibility and customization
Plug-ins to extend functionality for new or evolving storage managers
Support for foreign partition formats
Cluster-aware
1.2 Plug-In Layers
EVMS abstracts the storage objects in functional layers to make storage management more userfriendly. The following table describes the current EVMS plug-in layers for managing storage
devices and file systems:
Table 1-1 EVMS Plug-In Layers
Storage Managers Description Plug-Ins
Device Manages the physical and logical
devices
Segment Manages the partitioning of
physical and logical devices into
smaller segments of free space.
Segment managers can be
stacked. For example, a cluster
segment can contain other
storage objects or volumes.
Device Mapper (DM)
Uses Device Mapper (DM)
Segment managers include DOS,
GPT, System/390* (S/390),
Cluster, BSD, Mac, and BBR
For more information, see
Section 4.1, “Understanding Disk
Segmentation,” on page 35.
Overview of EVMS
11
Storage Managers Description Plug-Ins
novdocx (en) 13 May 2009
Regions Manages the combination of
multiple storage objects
EVMS Features Manages EVMS features Drive linking (linear
File System Interface Modules
(FSIM)
Cluster Manager Interface
Modules
Manages the interface between
the file system managers and the
segment managers
Manages the interface between
the cluster manager and the file
systems and devices
LVM/LVM2 for containers and
region, MD for RAIDs, and DM for
multipath I/O
concatenation), Bad Block
Relocation (BBR), and Snapshot
For information, see Section 1.3,
“Supported File Systems,” on
page 12.
HeartBeat 2
1.3 Supported File Systems
EVMS supports the following Linux file systems:
EXT3
ReiserFS
XFS
OCFS2
JFS
EXT2
Swap
NTFS (read only)
FAT (read only)
For more information about file systems supported in SUSE® Linux Enterprise Server 10, see the
SUSE Linux Enterprise Server 10 Installation and Administration Guide. (http://www.novell.com/
documentation/sles10).
The File System Primer (http://wiki.novell.com/index.php/File_System_Primer) describes the
variety of file systems available on Linux and which ones are the best to use for which workloads
and data.
1.4 Terminology
EVMS uses the following terminology in the EVMS user interface:
Table 1-2 EVMS Terms
Term Description
Sector The lowest level that can be addressed on a block device.
Disk A physical disk or a logical device.
12 SLES 10 SP2: Storage Administration Guide
Term Description
Segment An ordered set of physically contiguous sectors on a single device. It is similar
to traditional disk partitions.
Region An ordered set of logically contiguous sectors that might or might not be
physically contiguous. The underlying mapping can be to logical disks, disk
segments, or other storage regions.
novdocx (en) 13 May 2009
Feature
(Feature Object, EVMS
Feature, EVMS Object)
Storage Object Any storage structure in EVMS that is capable of being a block device. Disks,
Container
(Storage Container)
A logically contiguous address space created from one or more disks,
segments, regions, or other feature objects through the use of an EVMS
feature.
segments, regions, and feature objects are all storage objects.
A collection of devices that is managed as a single pool of storage.
Private Storage Container: A storage container that is exclusively owned and
accessed by only one server.
Cluster Storage Container: A storage container managed by the Cluster
Resource Manager. It is accessible to all nodes of a cluster. An administrator
can configure the storage objects in the cluster container from any node in the
cluster. Cluster containers can be private, shared, or deported.
Private: The cluster container is exclusively owned and accessed by only
one particular node of a cluster at any given time. The ownership can be
reassigned by failover policies or the administrator.
Shared: The cluster container is concurrently owned and accessed by all
nodes of a cluster. Shared containers are preferred for distributed
databases, clustered file systems, and cluster-aware applications that can
coordinate safe access to shared volumes.
Deported: The cluster container is not owned or accessed by any node of
the cluster.
Vol ume
(Logical Volume)
A mountable storage object. Logical volumes can be EVMS volumes or
compatibility volumes.
EVMS Volume: Volumes that contain EVMS metadata and support all
EVMS features. Device nodes for EVMS volumes are stored in the
directory. For example:
evms
/dev/evms/my_volume
/dev/
Compatibility Volume: Volumes that are backward-compatible to other
volume managers. They do not contain EVMS metadata and cannot
support EVMS features.
1.5 Location of Device Nodes for EVMS Storage Objects
EVMS creates a unified namespace for the logical volumes on your system in the
directory. It detects the storage objects actually present on a system, and creates an appropriate
device node for each one, such as those shown in the following table.
/dev/evms
Overview of EVMS 13
Table 1-3 Device Node Location
Storage Object Standard Location the Device Node EVMS Location of the Device Node
novdocx (en) 13 May 2009
A disk segment of disk
A software RAID device
An LVM volume
/dev/sda5
/dev/md1
/dev/lvm_group/lvm_volume
/dev/evms/sda5
/dev/evms/md/md1
/dev/evms/lvm/lvm_group/
lvm_volume
14 SLES 10 SP2: Storage Administration Guide
2
Using EVMS to Manage Devices
This section describes how to configure EVMS as the volume manager of your devices.
Section 2.1, “Configuring the System Device at Install to Use EVMS,” on page 15
Section 2.2, “Configuring an Existing System Device to Use EVMS,” on page 22
Section 2.3, “Configuring LVM Devices to Use EVMS,” on page 27
Section 2.4, “Using EVMS with iSCSI Volumes,” on page 27
Section 2.5, “Using the ELILO Loader Files (IA-64),” on page 28
Section 2.6, “Starting EVMS,” on page 28
Section 2.7, “Starting the EVMS Management Tools,” on page 28
2.1 Configuring the System Device at Install to Use EVMS
novdocx (en) 13 May 2009
2
This section describes how to configure the system device during the Linux install to use EVMS as
the volume manager instead of the current default of Linux Volume Manager (LVM).
Section 2.1.1, “Before the Install,” on page 15
Section 2.1.2, “During the Server Install,” on page 17
Section 2.1.3, “After the Server Install,” on page 20
2.1.1 Before the Install
“System Device” on page 15
“Device Size Limits” on page 16
“Data Loss Considerations for the System Device” on page 16
“Storage Deployment Considerations for the System Device” on page 16
System Device
For the purposes of this install documentation, a system device is any device that contains the Linux
/boot, swap
The install instructions assume the following:
All three system partitions are on the same physical disk.
, or root (/) partitions for your Linux computer.
If you use different disks for any of the system partitions, make sure to modify the install
instructions for your deployment scenario so that all of the system partitions are managed by
EVMS.
You must configure the boot partition within the BIOS-addressable space (such as 2 GB for x86
or 8 GB for x86-64) of the first disk recognized by the system.
If this restriction is not required for your hardware, you can modify the location of the
partition as desired.
Using EVMS to Manage Devices
/boot
15
Your system uses the Grub or LILO boot loaders.
If you have an IA64 system, you must modify these install instructions to use the ELILO boot
loader (
/boot/efi/elilo.conf
) instead.
novdocx (en) 13 May 2009
WARNING: Whenever you manually alter the kernel or
/sbin/elilo
run
before shutting down the computer. If you leave out this step, your system
initrd
on your system, make sure to
might not be bootable.
Device Size Limits
Version 2.3 and later of
mdadm
supports component devices up to 4 TB in size each. Earlier versions
support component devices up to 2 TB in size.
IMPORTANT: If you have a local disk, external disk arrays, or SAN devices that are larger than the
supported device size, use a third-party disk partitioner to carve the devices into smaller logical
devices.
md
You can combine up to 28 component devices to create the RAID array. The
RAID device you
create can be up to the maximum device size supported by the file system you plan to use. For
®
information about file system limits for SUSE
Linux Enterprise Server 10, see “Large File System
Support” in the SUSE Linux Enterprise Server 10 Installation and Administration Guide. (http://
www.novell.com/documentation/sles10).
Data Loss Considerations for the System Device
This install requires that you delete the default partitioning settings created by the install, and create
new partitions to use EVMS instead. This destroys all data on the disk.
WARNING: To avoid data loss, it is best to use the EVMS install option only on a new device.
If you have data volumes on the system device, take one or more of the following precautionary
measures:
Move the data volumes from the system device to another device.
If you cannot move the volumes, make a backup copy of the data, so you can restore the data
volumes later from a backup copy.
Storage Deployment Considerations for the System Device
By default, the YaST install for SUSE Linux Enterprise Server uses the Linux Volume Manager to
manage the system device. The install procedures in this section describe how to install SUSE Linux
Enterprise Server with EVMS as the volume manager of the system device. The instructions assume
the following:
You want to use EVMS to manage the system device.
Only the system device is to be configured during the install.
Other devices on the system are not configured during the install, or are attached to the server
later. These additional devices are configured only after the system is operating and performing
as expected.
16 SLES 10 SP2: Storage Administration Guide
2.1.2 During the Server Install
To install Linux with EVMS as the volume manager for your boot and system partitions, you must
modify the Partitioning configuration in the Installation Settings.
WARNING: The following procedure destroys all data on the system device.
1 Begin the install, according to the instructions provided in Deployment (http://
www.novell.com/documentation/sles10/sles_admin/data/part_setup.html) in the SUSE Linux
Enterprise 10 Installation and Administration Guide (http://www.novell.com/documentation/
sles10/sles_admin/data/bookinfo_book_sles_admin.html).
2 When the installation reaches the Installations Settings screen, delete the proposed LVM-based
partioning solution. This deletes the proposed partitions and the partition table on the system
device so that the device can be marked to use EVMS as the volume manager instead of LVM.
2a In the list of Installation Settings, select Partitioning.
2b In the Partitioning menu, select Create Custom Partition Setup, then click Next.
2c Select Custom Partition - for Experts, then click Next to open the Expert Partitioner
dialog box.
novdocx (en) 13 May 2009
2d Select Expert > Delete Partition Table and Disk Label, then click Yes twice to continue
through the Warning advisories.
This deletes the recommended partitions and the partition table on the system disk.
3 Create a primary partition on the system disk to use as the boot partition:
3a Click Create.
3b From the list of devices, select the device you want to use for the boot partition, such as
dev/hda
, then click OK.
If you have a single system disk, only one device is available, and you are not prompted to
choose the device.
3c Select Primary Partition, then click OK.
3d Select Format, then select the native Linux file system you want to use, such as Ext3.
IMPORTANT: In a paravirtualized environment, use Ext2 as the file system for the boot
device.
3e In Size (End Value) field, specify 200 MB or larger.
For example, to set the size at 300 MB, type
300M
.
3f Set the mount point to /boot.
3g Click OK.
The partition appears as a logical device in the devices list, such as
/dev/hda1
.
/
4 Create a second primary partition on the system disk to use for both the swap and system
volumes:
4a Click Create.
4b From the list of devices, select the device you want to use for the second primary partition,
such as
/dev/hda
, then click OK.
If you have a single system disk, only one device is available and you are not prompted to
choose the device.
Using EVMS to Manage Devices 17
4c Select Primary Partition, then click OK.
4d Select Do Not Format, then select Linux LVM (0x8E) from the list of file system IDs.
4e In Size (End Value field), set the cylinder End value to 5 GB or larger, depending on the
combined partition size you need to contain your system and swap volumes.
IMPORTANT: Do not make the system partition larger than necessary. The remaining
space on the system disk can be used to create NSS volumes or native Linux volumes that
are managed by EVMS.
To determing how much space to use, consider the following recommendations:
For your system volume, allow 2 GB (minimum) to 10 GB (recommended),
depending on the OES services that you intend to install.
If you intend to create additional NSS volumes on the same physical disk, you must
leave unpartitioned space available.
Set aside 128 MB or larger for the swap volume.
Swap management is different for Linux kernel 2.4.10 and later. How much swap to
add depends on the RAM size, the tasks that are planned for the system, and whether
you want to make more virtual memory available than the RAM provides.
Some swap (at least 128 MB) is good to have to minimize the risk of losing data
when active processes run out of RAM space. Swap is not required for systems with
more than 1 GB of RAM. You must have at least 1 GB of virtual memory (RAM plus
swap) during the install, but if the swap is more than 2 GB, you might not be able to
install on some machines.
novdocx (en) 13 May 2009
The total size should be the size you need for your system volume plus the size you
need for your swap volume.
For example, if you have a 20 GB hard drive with 2 GB of RAM and plan to install all of
the OES services on the system volume, your system partition should be at least 11 GB.
The remaining 9 GB should remain as free unpartitioned space that can be used for NSS
volumes or other Linux partitions that you might want to create later.
4f Click OK.
The partition appears as a logical device in the devices list, such as
/dev/hda2
.
5 Modify the volume management type from LVM to EVMS for the second primary partition
you created in Step 4:
5a At the bottom of the page, click EVMS.
Available partitions for EVMS appear as devices under
.
hda2
/dev/evms
, such as
/dev/evms/
5b In the EVMS Configurator, select the LVM partition created in Step 4, then click Create
Container.
5c In the Create EVMS Container dialog box, select the partition, specify the container name
(such as
system
system
is the container name.
), then click Add Volume to create the
lvm/system
container, where
5d Click OK.
The EVMS Configurator displays the
lvm/system
container you just created, its size, and
free space.
18 SLES 10 SP2: Storage Administration Guide
novdocx (en) 13 May 2009
6 Create the swap volume in the
6a Select
lvm/system
lvm/system
, then click Add.
container:
6b In the Create Logical Volume dialog box, select Format, then select Swap from the File
System drop-down menu.
swap
6c Specify
as the volume name.
6d Specify 1 GB (recommended) for the swap volume.
The swap size should be 128 MB or larger, with a recommended size of 1 GB. For an
explanation of this recommendation, see Step 4e.
6e Specify the mount point as swap.
6f Click OK.
7 Create the system volume in the
7a Select
lvm/system
, then click Add.
lvm/system
container:
7b In the Create Logical Volume dialog box, select Format, then select the file system to use
from the File System drop-down menu, such as Reiser or Ext3.
7c In the Volume Name field, specify a volume name, such as
sys_lx
.
7d In the Size field, click Max to set the size of the system volume as the remaining space
available in the
lvm/system
7e Specify the mount point as
partition.
/
(root volume).
7f Click OK.
8 Click Next to return to the list of devices.
Below is an example of the physical and logical devices that should be configured on your
system. Your setup depends on the number of devices in the server and the sizes you choose for
your partitions.
Device Size F Type Mount Start End Used By
/dev/hda
/dev/hda1
/dev/hda2
/dev/hdb
/dev/evms/lvm/system/
sys_lx
/dev/evms/lvm/system/
swap
149.0 GB 6Y160p0 0 19456
305.9 MB F Linux Native
(Reiser)
20.0 GB Linux LVM 39 2649 EVMS
111.8 GB SP1203N 0 14595
10.0 GB F EVMS
1.0 GB F EVMS
/boot
/
swap
038
--
--
9 Click Next to return to the Installation Settings page.
You can dismiss the message warning that you should not mix EVMS and non-EVMS
partitions on the same device.
10 Continue with the SUSE Linux Enterprise Server installation.
lvm/
system
Using EVMS to Manage Devices 19
IMPORTANT: After the install is complete, make sure to perform the mandatory post-install
configuration of the related system settings to ensure that the system device functions properly
under EVMS. Otherwise, the system fails to boot properly.
For information, see “After the Server Install” on page 20.
2.1.3 After the Server Install
After the SUSE Linux Enterprise Server 10 install is complete, you must perform the following
tasks to ensure that the system device functions properly under EVMS:
“Edit the /etc/fstab File” on page 20
“Make a New initrd” on page 21
“Disable the boot.lvm and boot.md Services” on page 21
“Enable the boot.evms Service” on page 21
“Restart the Server” on page 22
“Verify the System Services” on page 22
novdocx (en) 13 May 2009
Edit the /etc/fstab File
When you boot the system, the kernel reads the
/etc/fstab
file to identify which file systems
should be mounted and then mounts them. This file contains a table of file system information about
/
),
/boot
, and
swap
the root (
The
/boot
partition is separate from the EVMS container where you placed the root (/) and
partitions plus other partitions and file systems you want to mount.
swap
partitions and is not managed by EVMS at this time. However, in the following steps, you disable
boot.lvm
partitions at boot time, including the
directory. Therefore, this makes
requires that the device be listed under
with
so it is under the
In
fstab
/dev/sda1
as
SServeRA_Drive_1_600BC00000-part1
changed to include
The procedure in this section shows how to change
with the device name of the device you used for your
IMPORTANT: When working in the
and
boot.md
boot.evms
. You must edit the
, then enable
/dev/evms
/boot
/etc/fstab
directory.
boot.evms
/boot
. In effect, this forces EVMS to scan all the
partition, and it activates
/boot
under the
/dev/evms
a partition that is discovered by EVMS at startup, and
/dev/evms
in the
fstab
file so it can be found when booting
file to modify the location of the
/boot
partition
, the entry for the boot device might present the boot device by the device node name (such
) or by the UUID pathname (such as
/dev/disk/by-id/scsi-
). In ether case, that name for the boot device must be
evms
in the path, such as
/dev/evms/sda1
/etc/fstab
.
/dev/sda1
/boot
to
/dev/evms/sda1
partition.
. Replace
file, do not leave any stray characters or spaces
sda1
in the file. This is a configuration file, and it is highly sensitive to such mistakes.
To modify the path of the boot device in the
1 Open the
/etc/fstab
file in a text editor.
2 Locate the line that contains the
For example, if your
/boot
partition uses device
line similar to this:
20 SLES 10 SP2: Storage Administration Guide
/boot
/etc/fstab
partition.
sda1
file, complete the following procedure:
and the Reiser file system, look for a
/dev/sda1 /boot reiser defaults 1 1
3 In the Device Name column, modify the location of the
so it can be managed by EVMS. Modify only the device name by adding
evms
/boot
partition from
path:
/dev/evms/sda1 /boot reiser defaults 1 1
4 Save the file.
The changes do not take effect until the server is restarted. Do not restart at this time.
5 Continue with “Make a New initrd” on page 21.
Make a New initrd
/dev
/evms
to
novdocx (en) 13 May 2009
/dev/
to the
1 Open a terminal console, and log in as the
root
user.
2 At the console prompt, enter
mkinitrd
This creates a new
initrd
file with the correct settings for the boot device. The changes do not
take effect until the server is restarted. Do not restart at this time.
3 Continue with “Disable the boot.lvm and boot.md Services” on page 21.
Disable the boot.lvm and boot.md Services
Disable the
boot.lvm
and
boot.md
services so they do not run at boot time (runlevel B). EVMS
now handles the boot.
1 In YaST, click System > System Services (Runlevel) > Expert Mode.
2 Select boot.lvm.
3 Click Set/Reset > Disable the Service.
4 Select boot.md.
5 Click Set/Reset > Disable the Service.
6 Click Finish, then click Ye s.
The changes do not take effect until the server is restarted. Do not restart at this time.
7 Continue with “Enable the boot.evms Service” on page 21.
Enable the boot.evms Service
The
boot.evms
service should be enabled automatically after the install, but you should verify that
it is enabled.
1 In YaST, click System > System Services (Runlevel) > Expert Mode.
2 Select boot.evms.
3 Click Set/Reset > Enable the Service.
The B runlevel option is automatically selected.
4 Click Finish, then click Ye s.
The changes do not take effect until the server is restarted.
Using EVMS to Manage Devices 21
novdocx (en) 13 May 2009
NOTE: Effective in SUSE Linux Enterprise 10, the
nodes are automatically re-created on boot. It is no longer necessary to modify the
init.d/boot.evms
script to delete the device nodes on system restart, as was required for
/dev
directory is on
tmpfs
, and the device
/etc/
previous versions of SUSE Linux.
5 Continue with “Restart the Server” on page 22.
Restart the Server
1 Restart the server to apply the post-install configuration settings.
2 On restart, if the system device does not appear, it might be because EVMS has not been
activated. At the prompt, enter
evms_activate
Verify the System Services
After the post-install configuration is complete and you have restarted the server, make sure the
server is operating as expected.
2.2 Configuring an Existing System Device to Use EVMS
If you have already installed Linux with a different volume manager for the system device (that is,
the devices where you installed the
/boot, swap
configure the device for EVMS at any time after the install.
, or root (/) partitions), you can optionally
If you do not configure the device to use EVMS, you must manage the device and all of its volumes
with its current volume manager (the default is LVM), and free space on the device cannot be used
for volumes you want to create using EVMS. Beginning with the Linux 2.6 kernel, a given device
cannot be managed by multiple volume managers. However, you can have different volume
managers for different devices.
The following procedures assume that you installed Linux with three partitions on a single SCSI
sda
device named
/dev/sda1 reiserfs /boot
/dev/sda2 swap swap
/dev/sda3 reiserfs /
:
IMPORTANT: Make sure to modify the following procedures as necessary for your specific setup.
Section 2.2.1, “Disable the boot.lvm and boot.md Services,” on page 23
Section 2.2.2, “Enable the boot.evms Service,” on page 23
Section 2.2.3, “Edit the /etc/fstab File,” on page 23
Section 2.2.4, “Edit the Boot Loader File,” on page 24
Section 2.2.5, “Force the RAM Disk to Recognize the Root Partition,” on page 25
Section 2.2.6, “Restart the Server,” on page 26
Section 2.2.7, “Verify that EVMS Manages the Boot, Swap, and Root Partitions,” on page 26
22 SLES 10 SP2: Storage Administration Guide
2.2.1 Disable the boot.lvm and boot.md Services
novdocx (en) 13 May 2009
You need to disable
boot.lvm
(handles devices for Linux Volume Manager) and
boot.md
(handles
multiple devices in software RAIDs) so they do not run at boot time. In the future, you want
boot.evms
to run at boot time instead.
1 In YaST, click System > Runlevel Editor > Expert Mode.
2 Select boot.lvm.
3 Click Set/Reset > Disable the Service.
4 Select boot.md.
5 Click Set/Reset > Disable the Service.
6 Click Finish, then click Ye s.
The changes do not take effect until the server is restarted. Do not restart at this time.
7 Continue with Section 2.2.2, “Enable the boot.evms Service,” on page 23.
2.2.2 Enable the boot.evms Service
You need to enable the
1 In YaST, click System > Runlevel Editor > Expert Mode.
2 Select boot.evms.
3 Click Set/Reset > Enable the Service.
boot.evms
service so that it boots devices when you restart the server.
The B runlevel option is automatically selected.
4 Click Finish, then click Ye s.
The changes do not take affect until the server is restarted. Do not restart at this time.
NOTE: Effective in SUSE Linux Enterprise 10, the
nodes are automatically re-created on boot. It is no longer necessary to modify the
init.d/boot.evms
script to delete the device nodes on system restart as was required for
/dev
directory is on
tmpfs
and the device
/etc/
previous versions of SUSE Linux.
5 Continue with “Edit the /etc/fstab File” on page 23.
2.2.3 Edit the /etc/fstab File
When you boot the system, the kernel reads the
should be mounted and then mounts them. This file contains a table of file system information about
/boot, swap
the
You must edit the
mounted under the
Although the
, and root (/) partitions plus other partitions and file systems you want to mount.
/etc/fstab
/dev/evms
/boot
partition is not managed by EVMS, the
file to modify the mount location of these three partitions so they are
directory. For example, change
all the partitions at boot time, including the
directory. Therefore, this makes
evms
/boot
requires that the device’s path be listed under
booting with
boot.evms
.
/etc/fstab
/boot
partition, and it activates
file to identify which file systems
/dev/sda1
boot.evms
to
/dev/evms/sda1
script forces EVMS to scan
/boot
under the
.
/dev/
a partition that is discovered by EVMS at startup, and
/dev/evms
in the
fstab
file so it can be found when
Make sure to replace sda1, sda2, and sda3 with the device names you used for your partitions.
Using EVMS to Manage Devices 23
novdocx (en) 13 May 2009
IMPORTANT: When working in the
/etc/fstab
file, do not leave any stray characters or spaces
in the file. This is a configuration file, and it is highly sensitive to such mistakes.
1 Open the
2 Locate the line that contains the
For example, if your
/etc/fstab
/boot
file in a text editor.
/boot
partition.
partition uses device sda1 and the Reiser file system, look for a line
similar to this:
/dev/sda1 /boot reiser defaults 1 1
3 In the Device Name column, modify the mount location of the
dev/evms
so it can be managed by EVMS. Modify only the device name by adding
/boot
partition from
the path:
/dev/evms/sda1 /boot reiser defaults 1 1
4 Repeat Step 2 and Step 3 to edit the Device Name entry in the lines for the
partitions.
For example, change
.
sda3
/dev/sda2
to
/dev/evms/sda2
, and change
/dev/sda3
5 Save the file.
The changes do not take effect until the server is restarted. Do not restart at this time.
6 Continue with Section 2.2.4, “Edit the Boot Loader File,” on page 24.
swap
and root (/)
to
/dev
to
/
/evms
to
/dev/evms/
2.2.4 Edit the Boot Loader File
When you boot the system, the kernel reads the boot loader file for information about your system.
For Grub, this is the
/boot/grub/menu.1st
You must edit the boot loader file to modify the mount location of partitions so they are mounted
under the
/dev/evms
directory. For example, change /dev/sda1 to /dev/evms/sda1. Make sure to
replace the path for all lines that contain device paths in the files. You can modify the boot loader
file by editing fields in YaST, or use a text editor to modify the file directly.
IMPORTANT: When working in the boot loader file, do not leave any stray characters or spaces in
the file. This is a configuration file, and it is highly sensitive to such mistakes.
Using YaST
To modify the boot loader file in the YaST Control Center:
1 Log in as the
root
user or equivalent.
2 In Yast, select System > Boot Loader.
3 Modify the boot loader image so that the root file system is mounted as
/dev/
.
3a Select the boot loader image file, then click Edit.
3b Edit the device path in the Root Device field.
For example, change the Root Device value from
/dev/sda2
file. For LILO, this is the
/etc/lilo.conf
/dev/evms/
file.
instead of
24 SLES 10 SP2: Storage Administration Guide
to
/dev/evms/sda2
Replace
sda2
with the actual device on your machine.
3c Edit any device paths in the Other Kernel Parameters field.
3d Click OK to save the changes and return to the Boot Loader page.
4 Modify the failsafe image so that the failsafe root file system is mounted as
/dev/
instead of
.
/dev/evms/
4a Select the failsafe image file, then click Edit.
4b Edit the device path in the Root Device field.
4c Check the Other Kernel Parameters field and make changes if needed.
4d Click OK to save the change and return to the Boot Loader page.
5 Click Finish.
6 Continue with Section 2.2.5, “Force the RAM Disk to Recognize the Root Partition,” on
page 25.
novdocx (en) 13 May 2009
Using a Text Editor
To edit the boot loader file in a text editor:
1 Log in as the
root
user or equivalent.
2 Open the boot loader file in a text editor.
For Grub, this is the
3 Locate the line that contains the
/boot/grub/menu.1st
root=
parameter.
file. For LILO, this is the
/etc/lilo.conf
For example, if your root file system uses device sda1, look for a line similar to this:
kernel (sd0,0)/vmlinuz root=/dev/sda1 vga=0x31a splash=silent showopts
4 Modify the mount location from
/dev
to
/dev/evms
so it can be managed by EVMS.
For example, after the change, the line looks like this:
kernel (sd0,0)/vmlinuz root=/dev/evms/sda1 vga=0x31a splash=silent
showopts
5 Repeat Step 3 and Step 4 to locate other lines in the file that need to be similarly modified.
6 Save the file.
The changes do not take effect until the server is restarted. Do not restart at this time.
7 Continue with Section 2.2.5, “Force the RAM Disk to Recognize the Root Partition,” on
page 25.
file.
2.2.5 Force the RAM Disk to Recognize the Root Partition
The mkinitrd(8)
These RAM disk images are often used to preload the block device modules (SCSI or RAID) needed
to access the root file system.
You might need to force the RAM to update its device node information so that it loads the root (
partition from the
command creates file system images for use as initial RAM disk (initrd) images.
/dev/evms
path.
Using EVMS to Manage Devices 25
/
)
novdocx (en) 13 May 2009
NOTE: Recent patches to
mkinitrd
might resolve the need to do this task. For the latest version of
mkinitrd, see Recommended Updates for mkinitrd (http://support.novell.com/techcenter/psdb/
24c7dfbc3e0c183970b70c1c0b3a6d7d.html) at the Novell Technical Support Center.
root
1 At a terminal console prompt, enter the EVMS Ncurses command as the
user or
equivalent:
evmsn
2 Review the output to verify that EVMS shows only the
/boot
and
swap
partitions as active in
EVMS.
You should see the following devices mounted (with your own partition names, of course) for
these two partitions:
/dev/evms/sda1
/dev/evms/sda2
3 At a terminal console prompt, enter the following to update the
path information for the root (/) partition:
evms
/sbin/mkinitrd -f evms
initrd
image with the
This does not take effect until you restart the server.
4 Continue with Section 2.2.6, “Restart the Server,” on page 26.
2.2.6 Restart the Server
/dev/
1 Restart the server to apply the post-install configuration settings.
When your system restarts, the kernel loads the
init-ramdisk
, which runs the EVMS tools to
activate your volumes and mount your root file system. Then your boot scripts run the EVMS
tools once more to make sure your
/dev/evms/
directory correctly reflects the current state of
your volumes. Finally, the remaining EVMS volumes are mounted as specified in your
file. Everything else on your system should start up as you would normally expect.
fstab
2 Continue with Section 2.2.7, “Verify that EVMS Manages the Boot, Swap, and Root
Partitions,” on page 26.
2.2.7 Verify that EVMS Manages the Boot, Swap, and Root Partitions
1 At a terminal prompt, enter the EVMS Ncurses command as the
evmsn
2 Review the output to verify that EVMS shows the
/boot, swap
in EVMS.
You should see the following devices mounted (with your own partition names, of course)
under the
/dev/evms/sda1
/dev/evms/sda2
/dev/evms/sda3
/dev/evms
directory:
root
user or equivalent:
, and root (/) partitions as active
/etc/
26 SLES 10 SP2: Storage Administration Guide
2.3 Configuring LVM Devices to Use EVMS
Use the following post-installation procedure to configure data devices (not system devices) to be
managed by EVMS. If you need to configure an existing system device for EVMS, see Section 2.2,
“Configuring an Existing System Device to Use EVMS,” on page 22.
root
1 In a terminal console, run the EVMSGUI by entering the following as the
equivalent:
evmsgui
2 In the Vo l u me s panel, review the names that EVMS reports as compatibility volumes, find the
devices that represent the devices you want to manage using EVMS, then write down the
names for future reference.
For example,
/dev/sdb1
.
user or
novdocx (en) 13 May 2009
3 In a text editor, edit the
For example, change the following entry for an LVM2 volume from this
/dev/sdb1 / reiserfs defaults 1 2
to this
/dev/evms/lvm2/sdb1 / reiserfs defaults 1 2
IMPORTANT: Make sure not to leave any stray characters or spaces in the line.
With these changes, each time your system boots, your file system is mounted using EVMS as
the volume manager.
4 Update the boot scripts as follows:
The command
your volumes so they can be mounted.
If you run software-RAID (
and if you are moving all devices to EVMS, remove or disable those commands.
5 If you have not already done so, enable the
For information, see “Enable the boot.evms Service” on page 21.
6 Restart your system.
/etc/fstab
evms_activate
file to use the EVMS volume names.
must be run from your boot scripts in order to activate
boot.md
) or LVM (
boot.evms
boot.lvm
service.
) boot files in your boot scripts,
2.4 Using EVMS with iSCSI Volumes
If your EVMS devices, RAIDs, and volumes use storage devices from an iSCSI SAN, make sure
that your system starts iSCSI before EVMS so that the SAN and its disks are available to EVMS on
system startup. iSCSI must be started and running before any disks or volumes on the iSCSI SAN
can be accessed. If EVMS starts before iSCSI, EVMS cannot see or access the devices in the iSCSI
SAN to mount the storage objects they contain, so the EVMS devices, RAIDs, and volumes might
not be visible or accessible.
If EVMS starts before iSCSI on your system so that your EVMS devices, RAIDs, and volumes are
not visible or accessible, you must correct the order in which iSCSI and EVMS are started. Enter the
chkconfig
1 At a terminal console prompt, enter either
command at the Linux server console of every server that is part of your iSCSI SAN.
chkconfig evms on
Using EVMS to Manage Devices 27
or
chkconfig boot.evms on
This ensures that EVMS and iSCSI start in the proper order each time your servers restart.
2.5 Using the ELILO Loader Files (IA-64)
On a SUSE Linux Enterprise Server boot device EFI System Partition, the full paths to the loader
and configuration files are:
/boot/efi/SuSE/elilo.efi
/boot/efi/SuSE/elilo.conf
novdocx (en) 13 May 2009
When configuring partitioning during the install on IA64 systems, set the file system type for the
partition to
boot
vfat
, then choose Fstab Options and set the Arbitrary option value to
umask=077
/
to ensure that the partition is accessible only to administrators.
WARNING: Whenever you manually alter the kernel or
sbin/elilo
before shutting down the computer. If you leave out this step, your system might not be
initrd
on your system, make sure to run
bootable.
2.6 Starting EVMS
If EVMS does not start during the system boot, you must activate it manually.
1 Open a terminal console, then log in as the
root
user or equivalent.
2 At the terminal console prompt, enter
evms_activate
2.7 Starting the EVMS Management Tools
Use the following procedure to start the EVMS management tools.
IMPORTANT: When you are done, make sure to exit the EVMS UI tool. When it is running, the
EVMS UI tool locks the EVMS engine, potentially blocking other EVMS actions from taking place.
/
1 Open a terminal console, then log in as the
2 Enter one of the following commands to open the desired EVMS UI:
Command Description
evmsgui
evmsn
28 SLES 10 SP2: Storage Administration Guide
Starts the graphical interface for EVMS GUI. For information about features in
this interface, see ”EVMS GUI” (http://evms.sourceforge.net/user_guide/#GUI)
in the EVMS User Guide at the EVMS project on SourceForge.net.
Starts the text-mode interface for EVMS Ncurses. For information about
features in this interface, see the “EVMS Ncurses Interface” (http://
evms.sourceforge.net/user_guide/#NCURSES) in the EVMS User Guide at the
EVMS project on SourceForge.net.
root
user or equivalent.
Command Description
novdocx (en) 13 May 2009
evms
To stop
1 Close
evmsgui
evmsgui
Starts the EVMS commandline interpreter (CLI) interface. For information about
command options, see “EVMS Command Line Interpreter” (http://
evms.sourceforge.net/user_guide/#COMMANDLINE) in the EVMS User Guide
at the EVMS project on SourceForge.net.
from running automatically on restart:
.
2 Do a clean shutdown (not a restart).
3 Start the server.
When the server comes back up,
evmsgui
is not automatically loaded on restart.
Using EVMS to Manage Devices 29
novdocx (en) 13 May 2009
30 SLES 10 SP2: Storage Administration Guide
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