Hp COMPAQ PROLIANT 6000 High Performance Backup of Enterprise Servers

[February 1998

Compaq Computer
Corporation

CONTENTS

Introduction....................3

Test bed Description....... 4

Hardware......................... 4

Software.......................... 4

Performance

Demonstrations .............. 5

Case 1 – Local Flat File

Backup – Non RAIT .......... 5

Case 2 – Local Flat File

Backup – RAIT ................. 6

Case 3 – Local Relational

Database Backup ........... 11

Case 4 – Local Flat File

Restore – Non RAIT........ 12

Case 5 – Local Flat File

Restore – RAIT .............. 13

Case 6 – Local Relational

Database Restore........... 15

RAIT Tape Management .. 15
Data Migration Option

with Tape library Option .. 16
Disaster Recovery with

Tape Library Option ........ 16

DLT LIBRARY
PERFORMANCE BRIEF

High Performance Backup of Enterprise
Servers

Since its introduction in June1997, the Compaq DLT 15 Cartridge Library Model 1530
(Compaq 1530 Library) has been an industry leader in high performance backup
capabilities. The Compaq DLT 15 Cartridge Library Model 3570 (Compaq 3570 Library)
was announced in November 1997. This Library uses 35/70-GB DLT drives and sets new
standards in high-speed backup performance, capacity, and ease of use.

Late in 1997, Compaq performed a series of tests to examine the performance of the
Compaq 3570 Library. The objective of these tests was to find the highest-performance
configurations while performing realistic backup tasks on Compaq servers running
Windows NT 4.0 network operating system.

The Compaq 3570 Library provides high capacity, high-speed tape storage for use in
local and remote backup strategies. This brief addresses the technical aspects of high­performance backups that can reach and exceed 1651 gigabytes per hour (GB/hr) with
standard Compaq hardware.

Conclusion................... 17

APPENDIX 1.................. 18

Raw Performance Data.... 18

APPENDIX 2.................. 20

Standard Test System..... 20

APPENDIX 3.................. 21

Operating the Compaq

3570 Library .................. 21

APPENDIX 4.................. 22

DLT Media

Considerations ............... 22

APPENDIX 5.................. 25

Table of Figures ............. 25

ECG046/0298 1

Figure 1-- Compaq 3570 Library

1

Four Compaq 3570 Libraries with 8 35/70 DLT Drives running 8 concurrent jobs in a local (non-LAN) backup with data

compression of 4:1 can achieve this performance level. See the data in the appendix 1.

DLT LIBRARY PERFORMANCE BRIEF (cont.)

NOTICE

The information in this publication is subject to change without notice.

COMPAQ COMPUTER CORPORATION SHALL NOT BE LIABLE FOR TECHNICAL

OR EDITORIAL ERRORS OR OMISSIONS CONTAINED HEREIN, NOR FOR
INCIDENTAL OR CONSEQUENTIAL DAMAGES RESULTING FROM THE
FURNISHING, PERFORMANCE, OR USE OF THIS MATERIAL.

This publication does not constitute an endorsement of the product or products that were tested.
The configuration or configurations tested or described may or may not be the only available
solution. This test is not a determination of product quality or correctness, nor does it ensure
compliance with any federal, state, or local requirements. Compaq does not warrant products other
than its own strictly as stated in Compaq product warranties.

Product names mentioned herein may be trademarks and/or registered trademarks of their
respective companies.

Compaq, ProLiant, ProLinea, NetFlex, registered United States Patent and Trademark Office.
TriFlex Architecture and UltraView, CompaqCare and the Innovate logo, are trademarks and/or

service marks of Compaq Computer Corporation.
DLT is a trademark applied for by Quantum Corporation
Other product names mentioned herein may be trademarks and/or registered trademarks of their

respective companies.
©1998 Compaq Computer Corporation. Printed in the U.S.A.
Microsoft, Windows, Windows NT, Windows NT Advanced Server, SQL Server for Windows NT

are trademarks and/or registered trademarks of Microsoft Corporation.
ARCserve is a registered trademark of Computer Associates.
Lotus Notes is a registered trademark of IBM.

HIGH PERFORMANCE BACKUP OF ENTERPRISE SERVERS

High Performance Backup of Enterprise Servers

First Edition (January 1998)

ECG046/0298

ECG046/0298 2

Raid

RAID technology was
developed to improve
performance and
reliability of inexpensive
disk drives. Hence the
acronym Redundant

Array of Inexpensive
Drives. These systems

employ multiple drives to
improve the performance
and reliability of less
expensive drives.

When applied to tape
drives, system
performance and data
protection are most
important. For tape
systems, the acronym is

Redundant Array of
Independent Tape—

RAIT. Whatever the
acronym, the purpose is
the same, improved
performance and data
protection. Just remember
– RAIT is RAID
technology applied to
tape.

There are five techniques,
each offering unique
features to meet differing
speed and data protection
needs. These techniques
are referred to as levels.

RAID 0 offers greatest
speed. RAID 1 offers the
greatest data protection.
RAID 2, 3, 4 and 5 offer
high speed, with data
protection. The speed is
not as high as RAID 0,
and data protection is not
as great as RAID 1. Each
level offers features best
suited to a particular type
of hardware configuration
or operational

ECG046/0298 3

DLT LIBRARY PERFORMANCE BRIEF (cont.)

INTRODUCTION

The primary objective of this paper is to provide performance data for one or more Compaq Model
3570 DLT Libraries using RAID and non-RAID software technology. As more companies migrate
to server solutions to meet company data storage and retrieval requirements, system unavailability
during scheduled backup windows is a significant issue.

Operation has expanded to seven days a week and 24 hours a day. Concurrent (hot) backups with
the database in use, or small scheduled windows for backup are common practice. In either case,
shorter times to accomplish the task result in greater customer satisfaction.

Fault tolerance has become even more important with the large storage media prevalent today.
Statistically, as the volume of data increases, the number of faults increases. RAID 5 fault
tolerance technology allows a Library backup to complete successfully, even if a single tape drive
fails or one tape is missing or damaged. The data on the failed or missing tape is recoverable,
without requiring another backup.

Until the introduction of the Compaq Model 1530 DLT and Compaq Model 3570 DLT Libraries,
customers requiring tape RAID functionality needed to implement a Compaq DLT Tape Array. A
major disadvantage of this solution is that unattended data capacity is limited to a single tape
cartridge.

The Compaq Tape Array does not have the automation to remove and replace tapes. The Compaq
DLT Library products provide the automated functionality and capacity to eliminate the tedious
but necessary swapping of tapes. This automation permits backup scheduling during off-peak
hours, without an operator present to change tapes.

Libraries do not inherently have the ability to utilize RAIT. The backup software that supports the
library provides this functionality. Software products that support the Compaq Model 1530 and
Model 3570 DLT Libraries include Cheyenne ARCserve and Seagate Backup Exec. Of these, only
Cheyenne ARCserve 6.5 presently supports RAIT for the Compaq DLT Libraries.

Compaq, along with Cheyenne Software, a division of Computer Associates, can now provide the
automation and capacity of the DLT Library and the fault tolerance and performance of the DLT
Tape Array. Combining these features provides a reliable method of high-speed, automated
backups over a period of days or weeks without user intervention.

With the creation of the concept of a Virtual Library, Cheyenne ARCserve 6.5 allows management
of up to sixteen DLT Libraries and 32 DLT Drives as a single entity. A backup administrator can
easily manage multiple libraries from a single control point. The libraries may be physically
attached to any server on the LAN. The tape drives and cartridge slots in the physical libraries are
grouped together to form a single logical group, or pool. Multiple RAIDs of Libraries form pools
that can be viewed in ARCserve as a larger Virtual Library. The size of the pool is dynamically
adjustable by changing the defined RAID size to meet changing backup requirements. Pools of
Libraries can accommodate very large multi-terabyte databases, yet maintain the flexibility to
backup even the smallest remote office with the appropriately sized pool.

For ARCserve 6.5 running on one server, a maximum of sixteen Compaq 3570 Libraries (thirty­two 35/70 DLT Drives) per server can run 32 concurrent local backup jobs. Appendix 1 presents
the hardware environments used and details of performance measurements made for this white
paper.

The Compaq 1530 Library is the best choice for installations requiring a price/performance
tradeoff matching current LAN speeds and capacities2. Where maximum storage capacity and
performance are required, the Compaq 3570 Library is able to meet the demands. Regardless of the
needs of the installation, Compaq offers a state-of-the-art answer that meets current requirements
and will continue to do so in the future.

2

Current Ethernet 100Mbit/second LAN speeds allow a up to 35GB/Hr backup transfer rates with DB Agent and
compression at the source. An additional white paper, planned for later in 1998, will detail these limitations and techniques
to improve backups over the LAN.

DLT LIBRARY PERFORMANCE BRIEF (cont.)

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TEST BED DESCRIPTION

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Hardware

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ECG046/0298 4

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The Compaq ProLiant 6000 server was equipped with a Compaq

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Netelligent 10/100Mbit/s TX PCI Ethernet Controller. Compaq

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ProLiant 6000 features relevant to this test include four (4)

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200-MHz Pentium processors, 33-MHz PCI bus, and 100-MHz

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synchronous memory.

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Additional test bed details are discussed in Appendix 2.

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Hard Drive Array

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The server was equipped with four SMART/2 SCSI ‘RAID’ Hard Disk controllers feeding two

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channels of five Compaq 10K 9.1-GB Wide Ultra SCSI-3 hard drives. This provides a total of 364-

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GB per server. Older or non-Compaq hard drives may not be fast enough to keep pace with other

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backup components, and may be a significant performance bottleneck.

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The DLT Libraries were connected to SCSI cards with the Dual Channel Ultra Wide SCSI-3

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controllers. The use of a Compaq 32-bit Fast-Wide (SCSI-2) controller or the Ultra–wide

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integrated SCSI-3 controller for the DLT Library attachment is also possible. Use of other

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controllers may result in lower performance, and is not recommended. For additional details of

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system and SCSI channel-device attachment see Appendix 2, Standard Test System.

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Memory

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The server is populated with 320-MB main memory for these performance demonstrations. This is

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sufficient to prevent performance limitations due to insufficient memory.

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Software

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The operating system and backup software chosen for these tests is commercially available. Since

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Seagate Backup Exec does not support RAID, only ARCServe was used in testing. The software

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on each server was configured for optimum performance in accordance with the manufacturers

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recommendations.

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Operating System

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The server had Windows NT Server, version 4.0, build 1381 installed. Service pack 3 was also

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installed.

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Backup Software

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Cheyenne ARCserve version 6.5, Enterprise edition, build 600, with the Tape Library Option,

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RAIT Option, and Image Option was installed for these tests. The Tape Library Option specifically

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supports the Compaq 3570 and 1530 Libraries.

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Figure 2 -- Compaq ProLiant 6000

DLT LIBRARY PERFORMANCE BRIEF (cont.)

GB/Hr

PERFORMANCE DEMONSTRATIONS

Case 1 – Local Flat File Backup – Non RAIT

Case 1 demonstrates local backup performance. Figure 3 illustrates this network, consisting of a
single Compaq ProLiant 6000 server with four Compaq 3570 Libraries attached.

Figure 3 -- Flat File Network

Image Backup

This test demonstrates image backup performance from a single Compaq ProLiant 6000 server to
one, two, and four Compaq 3570 Libraries. Cheyenne ARCserve 6.5 image backup copies all used
blocks from the storage media to the backup media.

The total volume of data was 364-GB. The data for this test was compressible at a 4:1 ratio3. The
results of this test, presented in Figure 4, demonstrate the performance improvements obtainable
from additional Compaq 3570 Libraries. Each additional library, which houses two 35/70 DLT
drives, allows the addition of two jobs.

180
160
140
120
100

80
60
40
20

0

2 4 8

Jobs

ECG046/0298 5

Figure 4 -- Flat File Performance – Multiple Jobs

3

The compression ratio of data is a key factor in backup performance. For estimated compressibility of several types of data
files, refer to appendix 4.

DLT LIBRARY PERFORMANCE BRIEF (cont.)

Case 2 – Local Flat File Backup – RAIT

These tests demonstrate local backup tasks. A single Compaq ProLiant 6000 server has from one
to four Compaq Model 3570 DLT Libraries attached. Image backup tasks were tested. The files are
simple flat (non-relational) files. Figure 3 illustrates this network with four Compaq 3570 Libraries
attached to the Compaq ProLiant 6000.

ARCserve 6.5 will operate the Compaq Model 3570 DLT Libraries in RAIT 0, RAIT 1, or RAIT 5
configurations. RAIT 0 typically yields highest performance. RAIT 1 offers the greatest protection
for the data. RAIT 5 retains up to 80% of the speed performance, with data protection.

RAIT 0 stripes the data block across two or more tapes. These tapes may be mounted on one
library if only two drives are used, or the tapes may be in different libraries. This is the highest
performance configuration, but there is no data redundancy. If a fault occurs in any tape, the entire
data set may be lost. Figure 5 illustrates RAIT 0 data distribution across three tapes.

A potential performance limitation exists in the way applications software, such as ARCServe,
launches threads and the way the Windows NT processes those threads. Launching concurrent
tasks will start more threads, thus improving time slicing and backup efficiency.

ECG046/0298 6

Figure 5 -- RAIT 0 Data Distribution

DLT LIBRARY PERFORMANCE BRIEF (cont.)

ARCserve 6.5 RAIT 1 mirrors both 35/70 GB LT drives in one Compaq 3570 Library. Each 35/70
GB DLT drive receives identical data. If there is a failure in one library during either reading or
writing, the data on the other drive is intact. This configuration is more secure than RAIT 0, but
does not take full advantage of the capacity and performance benefits available from the Compaq
3570 Library. Figure 6 illustrates mirroring data to two tapes.

ECG046/0298 7

Figure 6 -- RAIT 1 Data Mirroring

It is also possible to create automatic off-site backups using a configuration with two Compaq
Model 3570 DLT Libraries physically in different locations while connected to the same network.
The server and one library are connected locally, with a second library attached to the network, but
physically located in a remote location. Since RAID is not currently supported over a network, one
job is run locally, and a second job backing up the same files is run to the remote library over the
network. This would limit backup performance to that of the LAN.

DLT LIBRARY PERFORMANCE BRIEF (cont.)

RAIT 5 retains up to 80% of the performance benefit of RAIT 0 while adding fault tolerance. Each
data block is striped across three or more tapes, a parity code is calculated for each block, and that
parity code is stored on another tape. The data and parity rotate among all tapes in the Virtual
Library. The Virtual Library concept permits mounting the tapes in a single backup set in different
libraries. Since each Compaq 3570 Library houses two 35/70 DLT Drives, this concept is essential
in order to operate the library in RAIT 5. Figure 7 illustrates RAIT 5 data and parity placement
across five tapes.

HOST SYSTEM

Parallel Data Queue

Parity

data
data
data
data

Parity

data
data

data

Parity

Figure 7-- RAIT 5 Writing Pattern

data

Parity

data
data

data

datadatadata data
data
data

Parity

data

datadata

data
data
data

Parity

data

ECG046/0298 8