Sun™ Enterprise™ Server
Alternate Pathing 2.1
Reference Manual
Part No. 805-5443-10
May 1998, Revision A
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AP Commands Intro ( 1M )
NAMEIntro–AP administration
DESCRIPTIONThis section describes commands, scripts, and programs executed in the Alternate
Pathing environment.
LIST OF
COMMANDS
ap(1M) alternate pathing
ap_daemon(1M) alternate pathing daemon
ap_reboot_host(1M) fast boot alternate path
ap_ssp_daemon(1M) AP SSP daemon
apboot(1M) set up system files for boot meta-disk
apcheck(1M) determine accessibility of a meta-disk
apconfig(1M) display and manage AP configuration
apdb(1M) manage AP database
apdisk(1M) manage disk pathgroups
apinst(1M) identify disk host adapter instances, /dev/dsk targets
apnet(1M) manage network pathgroups
apssp(1M) client of AP SSP daemon
AP 2.1 1M-1
ap ( 1M ) AP Commands
NAMEap–alternate pathing
DESCRIPTIONAlternate Pathing (AP) enables you to define and control alternate physical paths to
peripheral devices. If a path to a device becomes unavailable, your Sun server can use
an alternate path.
SEE ALSOSun Enterprise Server Alternate Pathing User’s Guide
1M-2 AP 2.1
AP Commands ap_daemon ( 1M )
NAMEap_daemon–alternate pathing daemon
SYNOPSIS ap_daemon
DESCRIPTION /usr/sbin/ap_daemon is an RPC program that provides the interface to the Alternate
Pathing (AP) driver.
Configuration
Information
The ap_daemon RPC program name is AP_SVR, its RPC program number is 300473,
and its underlying protocol is TCP. It is invoked as an inetd server via the TCP transport. The UID required for access to the daemon is ssp. This UID can be a non-login
UID.
The entry for the daemon in the /etc/inetd.conf file is:
SEE ALSOSun Enterprise Server Alternate Pathing User’s Guide
apconfig(1M), apdb(1M), apdisk(1M), apnet(1M)
AP 2.1 1M-3
ap_reboot_host ( 1M ) AP Commands
NAMEap_reboot_host–fast boot alternate path
SYNOPSIS ap_reboot_host
AVAILABILITYSun Enterprise 10000 servers only.
DESCRIPTION Caution: Do not execute ap_reboot_host on the command line; it is intended for use
only by other commands.
$SSPOPT/bin/ap_reboot_host is executed when a boot failure is detected. It deter-
mines the boot path of the previous boot and attempts to restart the host from an alternate path if one is available.
1M-4 AP 2.1
AP Commands ap_ssp_daemon ( 1M )
NAMEap_ssp_daemon–AP SSP daemon
SYNOPSIS ap_ssp_daemon
AVAILABILITYSun Enterprise 10000 servers only. This command is executed in the SSP environment.
DESCRIPTION $SSPOPT/bin/ap_ssp_daemon is an RPC program that maintains an SSP-based file
that contains Alternate Pathing (AP) information for the boot disks. This file is updated
automatically by ap_daemon(1M).
ap_ssp_daemon provides its information to apssp(1M), which then passes it to
ap_reboot_host(1M). The SSP program apssp(1M) provides the interface to
ap_ssp_daemon.
The daemon’s only clients are apssp(1M) and ap_daemon(1M). apssp(1M) provides a
way to access the information the daemon keeps. ap_daemon(1M) updates the information.
SEE ALSO ap_daemon(1M), ap_reboot_host(1M), apssp(1M)
DESCRIPTIONUse /usr/sbin/apboot to edit /etc/vfstab and /etc/system to make the system bootable
from either the boot disk file systems on an AP meta-disk or the boot disk file systems
on a disk device that is not alternately pathed; or to allow AP to coherently manage a
mirrored boot device when both that boot device and its mirror are under AP control.
OPTIONS
EXAMPLES apboot mc3t0d0
FILES /etc/systemkernel patch file
–
nPrint what would be done without actually doing it.
–
k system-name
Edit system-name instead of the default /etc/system file.
–
v vfstab-name
Edit vfstab-name instead of the default /etc/vfstab table of file system defaults.
–
m metadevice-name
Enable boot mirror support for the specified AP meta-device.
–
u metadevice-name
Disable boot mirror support for the specified AP meta-device.
Edits /etc/system and /etc/vfstab to specify that the boot disk file systems are
now on meta-disk mc3t0d0.
apboot c3t0d0
Edits /etc/system and /etc/vfstab to specify that the boot disk file systems are
now under the physical path /dev/dsk/c3t0d0.
apboot mc3t0d0
apboot -m mc1t0d1
These commands edit /etc/system and /etc/vfstab to specify that the boot disk
file systems are now on meta-disk mc3t0d0, with a mirror on mc1t0d1.
apboot -u mc1t0d1
Disables AP support for the mirror device created in the previous example.
/etc/vfstabtable of file system defaults
SEE ALSO system(4), vfstab(4) in man Pages(4): File Formats of the SunOS Reference Manual
1M-6 AP 2.1
AP Commands apcheck ( 1M )
NAMEapcheck–determine accessibility of a meta-disk
SYNOPSIS apcheck special
DESCRIPTION Caution:Do not execute apcheck on the command line; it is intended for use
only by other commands, or by authorized service providers.
/sbin/apcheck ascertains whether a meta-disk is usable. If it is able to locate dual
paths, apcheck exits with a zero status; if not, it exits with a non-zero status.
OPTIONspecial represents the device node to be checked. This device node may reside under
DESCRIPTIONThe /usr/sbin/apconfig command displays and helps you manage the Alternate Pathing
(AP) system configuration.
OPTIONS
–
DDisplay location and status information for all known copies of the
host database.
–
FForce the state (attached or detached) of every committed pathgroup
alternate to match the physical state of the system. Use this option if
the two states differ. It refreshes the Dynamic Reconfiguration (DR)
flags for every disk I/O port and physical network interface defined
for all committed pathgroups.
–
N [–u] Display network AP information only. For each pathgroup,
apconfig–N displays the meta-network interface and the correspond-
ing physical network interfaces.
If you specify the–u option, apconfig displays uncommitted path-
group information only. If you do not specify the–u option, apconfig
displays committed pathgroup information only. See Letters afternames and paths, below.
–
P meta_ntwrk_intrfc–a new_phys_path
Switch to the new physical path specified by–a for the meta-network
specified by -P.
–
P primary_path–a new_phys_path
Switch to the new physical path specified by–a for the primary path
specified by -P.
–
RRebuild the meta-disk device nodes in /dev/ap/dsk and /dev/ap/rdsk.
apconfig creates links to /devices for all committed disk pathgroups in
the database.
Note:You must execute drvconfig–i ap_dmd before you
can execute apconfig–R. See drvconfig(1M) and
ap_dmd(7).
–
S [–u] Display alternate pathing information for disk pathgroups only. (S
stands for SCSI.) For each pathgroup, apconfig shows the names for
the meta-disk, its physical devices, and the disk I/O ports through
1M-8 AP 2.1
AP Commands apconfig ( 1M )
which each physical device is accessed.
If you specify the–u option, apconfig displays only uncommitted
pathgroup information. Otherwise, it displays only committed pathgroup information. See Letters after names and paths, below.
Letters after names
and paths
When you specify–N or–S, one or more of the following letters may be displayed
after each meta-network or meta-disk name:
D Marked for deletion. The meta-disk or meta-network remains in the data-
base and continues to be used by AP until a commit is done. See
apdb(1M).
U Uncommitted. Note that you cannot use a meta-disk or meta-network until
a commit has been done.
RMarked for use as a root device.–S only.
M Marked as the mirror for a boot device.–S only.
XThe physical paths for this meta-disk lead to different disks (i.e., different
SSA’s).–S only.
When you specify–N or–S, one or more of the following letters may be displayed
after each physical network name or disk I/O port name:
A The active alternate. To select another interface, use the -P and -a options.
DR
Marked as being drained by Dynamic Reconfiguration. A switch cannot be
made to a device path in this state. See the Sun Enterprise Server AlternatePathing User’s Guide.
DE Marked as detached by Dynamic Reconfiguration.
PThe primary path. The primary path cannot be changed.
TPath has been tried as active.
O Marked as offline. See apdisk(1M) and apnet(1M).
EXAMPLES
Example 1The following example displays all committed disk pathgroups in the AP database:
# apconfig -S
c6 pln0 A
c2 pln3 P
metadiskname(s):
mc2t5d0
mc2t4d0 R
mc2t3d0
mc2t2d0
mc2t1d0
AP 2.1 1M-9
apconfig ( 1M ) AP Commands
mc2t0d0
Example 2The following example displays all uncommitted network pathgroups in the AP data-
base.
# apconfig -N -u
meta-network: mqe0 U
physical devices:
qe1
qe0 P A
Example 3The following example switches the active alternate of the disk pathgroup for which
the primary path is pln1. The new active alternate of that pathgroup is pln0.
# apconfig -P pln1 -a pln0
Example 4The following example switches the active alternate of the network pathgroup
identified by the meta-network interface mqe0. The new active alternate of that network pathgroup is qe1.
# apconfig -P mqe0 -a qe1
Example 5The following example displays the location and status information of all known
copies of the AP database.
# apconfig -D
path: /dev/rdsk/c3t3d0s1
major: 32
minor: 145
timestamp: Wed Sep 28 18:45:58 1994
checksum: 2636010350
default: yes
corrupt: no
inaccessible: no
SEE ALSOSun Enterprise Server Alternate Pathing User’s Guide
apdb(1M), apdisk(1M), apnet(1M), ap_dmd(7) in this reference manual
drvconfig(1M) in man Pages(1M): System Administration Commands of the SunOS Reference
DESCRIPTIONThe /usr/sbin/apdb command helps you manage the AP database.
OPTIONS
–
c raw_disk_slice
Create a database copy on the specified raw disk slice. You can create
up to 10 copies of the database. The minimum slice size is 300KBytes.
–
d raw_disk_slice
Delete a database copy from the specified raw disk slice.
–
fForce deletion of the specified database. This option is required for
creating the first copy of the database, and when deleting each of the
last two copies of the database. If you try to delete a database copy
without this option when fewer than two database copies exist, AP
displays an error message.
–
k system_filePatch the the database copy information to the kernel file system_file,
rather than the default file, /etc/system.
–
m major–n minor
Remove a database copy by specifying its location as a major-minor
pair. Use–m to specify the major and–n for the minor. This option
pair is useful when there is no path to the database because the device
no longer exists.
–
CCommit all uncommitted entries within the database.
–
ZCopy the database in memory to all database copies. Note that all
database copies are in sync with memory and are automatically
updated at system shutdown.–Z lets you update the database copies
at your discretion.
EXAMPLEThe following example creates a copy of the AP system database on
/dev/rdsk/c2t0d0s1.
# apdb -c /dev/rdsk/c2t0d0s1
SEE ALSOSun Enterprise Server Alternate Pathing User’s Guide
DESCRIPTIONThe /usr/sbin/apdisk command helps you manage disk pathgroups in the Alternate
Pathing (AP) system.
OPTIONS
–c–
p primary_path–a alternate_path
Create database entries for disks (i.e., a SPARCStorage Arrays) connected to two I/O ports. Give the I/O port names (e.g., pln0 and
pln1) as the primary_path and alternate_path.
–
d primary_path
Delete AP information for the specified disk pathgroup. If the existing
information is uncommitted, apdisk removes it immediately. If the
existing information is already committed, it is only marked for deletion and existing meta-devices continue to function until a commit is
done, at which time the information is removed.
–
z primary_path
Undelete AP information for the specified disk pathgroup. This option
cancels a previous apdisk–d request that marked committed information for deletion.
–
f io_portMark the I/O port as offline. Corresponding meta-disks can still be
used if the other I/O port in the pathgroup is functioning properly.
Note that you cannot mark an I/O port offline if it is currently the
active alternate.
–
n io_portMark the I/O port as online. Note that this operation does not
automatically cause the I/O port to become the active alternate.
–u–
p primary_path–a alternate_path
Update existing database entries for the disk pathgroup identified by
the primary path (e.g., pln0). Disk targets that are no longer accessible
through one or more paths are removed, and new disk targets are
added. To update the meta-disk device nodes execute
drvconfig–i ap_dmd and apconfig–R. See apconfig(1M) in this docu-
ment and drvconfig (1M) in man Pages(1M): System Administration Com-mands of the SunOS Reference Manual.
AP 2.1 1M-13
apdisk ( 1M ) AP Commands
–
w io_portClear the tried flag for the specified I/O port.
EXAMPLES
Example 1The following example creates meta-disk device nodes and AP database entries for
disks reachable through pln0 and pln1, with pln0 specified as the primary path.
Example 2The following example deletes the AP database entries for disks with sf1 specified as
the primary path.
# apdisk -d sf1
# apdb -C
SEE ALSOSun Enterprise Server Alternate Pathing User’s Guide
apdb(1M), apconfig(1M), apinst(1M), apnet(1M) in this reference manual
devlinks(1M), drvconfig(1M) in man Pages(1M): System Administration Commands of the
SunOS Reference Manual
1M-14 AP 2.1
AP Commands apinst ( 1M )
NAMEapinst–identify disk host adapter instances, /dev/dsk targets
SYNOPSIS apinst
DESCRIPTIONThe /usr/sbin/apinst program identifies all disk host bus adapters and provides the
name, instance number and /dev/dsk targets attached to each.
DESCRIPTIONThe /usr/sbin/apnet command helps you manage network pathgroups in the Alternate
Pathing (AP) system.
OPTIONS Note:The parameters meta_ntwk_intrfc and ntwk_intrfc are strings of the form
type instance_#, but with no space between them; for example, mle0 and mle1.
–
c -p ntwk_intrfc [–a ntwk_intrfc]
Create a meta-network interface and network pathgroup for the
specified network. If–a is given, apnet designates the specified network interface as the alternate for the meta-network interface. (If you
initially create a network pathgroup with only one path, you can later
add an additional path using apnet -m.)
–
d meta_ntwk_intrfc
Delete the specified meta-network interface and corresponding network pathgroup. If the pathgroup is currently uncommitted, apnet
removes the interface and the pathgroup immediately. If the pathgroup
is committed, the interface and pathgroup are only marked for deletion, and the interface continues to function until a commit is performed.
–
z meta_ntwk_intrfc
Undelete the specified meta-network interface and pathgroup. This
option cancels a previous apnet–d request that marked a committed
pathgroup for deletion.
–
f ntwk_intrfcMark the specified network interface as offline and therefore inaccessi-
ble through its meta-network interface.
Note:An interface cannot be marked as offline if it is active.
–
n ntwk_intrfc Mark the specified network interface as online and therefore accessible
through its meta-network interface.
1M-16 AP 2.1
AP Commands apnet ( 1M )
–
m meta_ntwk_intrfc–a ntwk_intrfc
Add the specified network interface as the alternate for the specified
network pathgroup. You can use this option only if the network pathgroup currently contains exactly one path.
–
m meta_ntwk_intrfc–r ntwk_intrfc
Remove the specified network interface from the specified network
pathgroup.
Note:When an alternate is added (–a) or removed (–r) from a com-
mitted network pathgroup, a commit operation must be done
for the change to take effect. In practice, the existing metanetwork interface is marked for deletion and a new one is
created without affecting current usage of the interface.
–
t meta_ntwk_intrfc
Make the next alternate path in sequence (after the primary) the temporary active path. This option is intended for scripts that are trying
alternate paths in sequence until a working path is found. The command returns an error if the sequencing wraps back to the original primary.
–
w meta_ntwk_intrfc
Make the current temporary active path the actual active path.
EXAMPLES
Example 1The following example creates a network pathgroup and a meta-network interface,
mle0, which has le0 as its primary physical network interface and le1 as its alternate
physical network interface.
# apnet -c -p le0 -a le1
# apdb -C
Example 2The following example deletes the network pathgroup and meta-network interface
mle0:
# apnet -d mle0
# apdb -C
SEE ALSOSun Enterprise Server Alternate Pathing User’s Guide
apconfig(1M), apdb(1M), apdisk(1M)
AP 2.1 1M-17
apssp ( 1M ) AP Commands
NAMEapssp–client of AP SSP daemon
SYNOPSIS apssp
AVAILABILITYSun Enterprise 10000 servers only.
DESCRIPTION Caution:Do not execute apssp on the command line; it is intended for use only
by other commands.
apssp is a client of the Alternate Pathing SSP daemon, ap_ssp_daemon(1M). It takes
information from ap_ssp_daemon and passes it to ap_reboot_host(1M).
SEE ALSO ap_ssp_daemon(1M), ap_reboot_host(1M)
1M-18 AP 2.1
AP Special Files Intro ( 7 )
NAMEIntro–AP special files
DESCRIPTIONThis section describes AP files for your Sun server.
LIST OF
FUNCTIONS
ap(7) alternate pathing librarian driver, /dev/ap
ap_dmd(7) AP disk meta-driver
ap_nmd(7) AP network meta-driver group
mhme(7) Sun FastEthernet 2.0; see ap_nmd(7)
mle(7) Lance Ethernet special character device; see ap_nmd(7)
mnf(7) FDDI 3.0.x and 4.x special character device; see ap_nmd(7)
mqe(7) Quad Ethernet special character device; see ap_nmd(7)
mqfe(7) Quad Fast Ethernet special character device; see ap_nmd(7)
mvge(7) Sun Gigabit Ethernet special character device; see ap_nmd(7)
DESCRIPTIONThe AP driver provides a pseudo-driver interface to the kernel Alternate Pathing (AP)
Librarian features.
FILES /kernel/drv/apAP driver module
/kernel/drv/ap.confAP driver configuration file
SEE ALSOSun Enterprise Server Alternate Pathing User’s Guide
ap(1M), ap_daemon(1M)
7-2 AP 2.1
AP Special Files ap_dmd ( 7 )
NAMEap_dmd–AP disk meta-driver
SYNOPSIS ap_dmd@target,lun:partition
DESCRIPTIONThe ap_dmd driver works with the AP software to support Alternate Pathing for phy-
sical devices handled by the ssd SCSI disk driver. See ssd(7) in man Pages(7): Device
and Network Interfaces of the SunOS Reference Manual.
The AP feature lets you configure alternate SCSI paths to a physical device. These
paths are associated with a meta-disk device, which is one of the file system special
nodes associated with a particular meta-driver.
ap_dmd allows the AP Librarian, ap(7), to configure or unconfigure physical paths to a
SCSI device via an interface that allows APSET, APUNSET, and APSWITCH commands. These commands are issued by ap(7) at the behest of the user-invoked AP
commands and AP daemon. To change the SCSI path information associated with a
particular ap_dmd device, use apconfig(1M), apdb(1M) and apdisk(1M). For more
information, see the Sun Enterprise Server Alternate Pathing User’s Guide.
All device operations supported by the ssd driver are also valid on ap_dmd devices
that have been created via AP commands. See the other AP commands for details
regarding other components of AP software, and ssd(7) man page for information
about block/character file accesses, I/O requests, disk partitioning schemes, CD-ROM
support, and ioctls.
ERRORS ENXIONo physical SCSI path to the target device exists.
DESCRIPTION ap_nmd is a group of multi-threaded, loadable, clonable, STREAMS meta-network
device drivers that support the connectionless Data Link Provider Interface, dlpi(7), for
hme(7) (Sun FastEthernet 2.0), le(7) (Lance Ethernet), nf(7) (FDDI 5.x), qe(7) (QuadEthernet), qfe (Quad FastEthernet), and vge (Sun Gigabit Ethernet).
Note:SunOS man pages that describe drivers for optional packages, such as
FDDI and Sun FastEthernet, are available only on systems that have those
packages installed.
ap_nmd works with the AP software to support Alternate Pathing for physical net-
work devices.
Device operations of ap_nmd are an extension of the operations of the underlying network drivers. ap_nmd normally operates as a transparent pass-through module; it neither interprets nor modifies any of the STREAMS DLPI type messages. However, it
does intercept and modify the DL_ATTACH_REQ and DL_INFO_ACK messages.
DL_ATTACH_REQ messages are captured and used to drive the initial connection
between logical and physical devices. DL_INFO_ACK messages are captured and
responded to with a prebuilt response to eliminate the possibility of the message
response timing out due to induced message delays.
The cloning character-special device /dev/m xx is used to access all device-specific
instances of the ap_nmd within the system.
ap_nmd and APThe ap_nmd driver provides an interface to support Alternate Pathing. The APSET
interface allows a user to provide a mapping between physical path and logical path.
The APUNSET provides an interface to remove a physical-to-logical path mapping and
APSWITCH provide a mechanism to switch a logical path from its existing physical
path to a new physical path. For a more complete description of the AP capability, see
the Sun Enterprise Server Alternate Pathing User’s Guide.
ap_nmd and DLPIThe ap_nmd driver is a "style 2" Data Link Service provider. All DLPI processing is
handled by the underlying physical device driver. See the man page that corresponds
to each underlying driver.
ERRORS EBUSYAn attempt was made to unload a busy device, or to APUNSET an
active device
7-4 AP 2.1
AP Special Files ap_nmd ( 7 )
EEXISTAn attempt was made to APSET an existing logical-to-physical map-
ping and a logical path when the system was out of memory
EIOAn attempt to switch between physical devices failed
ENODEVNo physical mapping exists
ENOMEMSystem memory was exhausted during an attempt to create a mapping
/dev/mhmehme special character device
/dev/mlele special character device
/dev/mnfnf special character device
/dev/mqeqe special character device
/dev/mqfeqfe special character device
/dev/mvgevge special character device
DIAGNOSTICSSee le(7) and qe(7) in man Pages(7): Device and Network Interfaces of the SunOS Reference
Manual.
SEE ALSOSun Enterprise Server Alternate Pathing User’s Guide
ap_daemon(1M), apconfig(1M), apdb(1M), apnet(1M), ap(7), ap_dmd(7), in this refer-
ence manual
driver.conf(4) in man Pages(4): File Formats of the SunOS Reference Manual
man Pages(7): Device and Network Interfaces of the SunOS Reference Manual and other
optional reference manuals (for example, FDDI Reference Manual), as appropriate
AP 2.1 7-5
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