How to achieve over 2 TB/hr network backup with Integrity entry-class servers running HP-UX 11i v3

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How to achieve over 2 TB/hour network

backup with Integrity entry-class servers

running HP-UX 11i v3

Technical white paper

Table of contents

Introduction ......................................................................................................................................... 2

Objectives .......................................................................................................................................... 2

Testing methodology ............................................................................................................................ 2

Test environment configuration .............................................................................................................. 3

Backup server configuration .............................................................................................................. 4

Client system configurations .............................................................................................................. 4

Additional test environment configuration details ................................................................................. 5

Identifying solution limits, stress points, and optimal tuning ....................................................................... 5

Backup utility tuning testing ............................................................................................................... 5

One-gigabit Ether port limit testing ..................................................................................................... 7

HP StorageWorks Ultrium 1840 LTO-4 limit testing .............................................................................. 8

4Gb FC HBA port limit testing ........................................................................................................... 9

Test results: implications for optimizing the test environment ................................................................ 10

Analysis of test results for backup servers and client systems ................................................................... 10

Backup server results ...................................................................................................................... 10

Client server results......................................................................................................................... 13

Best practices .................................................................................................................................... 15

Taking advantage of HP-UX 11i v3 features ...................................................................................... 15

Tape library and device considerations ............................................................................................ 20

Balancing backup data streams ....................................................................................................... 20

Private backup network considerations ............................................................................................. 20

Monitoring link utilization of APA ..................................................................................................... 21

Considering the uniqueness of each backup environment .................................................................... 21

Minimizing the server hardware footprint in the data center ................................................................ 21

Optimizing for mission-critical applications and high-demand environments .......................................... 22

Summary of test results ....................................................................................................................... 23

Conclusion ........................................................................................................................................ 25

For more information .......................................................................................................................... 27

Summary of content (28 pages)

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How to achieve over 2 TB/hour network backup with Integrity entry-class servers running HP-UX 11i v3 Technical white paper Table of contents Introduction ......................................................................................................................................... 2 Objectives .......................................................................................................................................... 2 Testing methodology ..............................................
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Introduction Network backup (also known as remote backup) is widely used today in environments where servers with anywhere from a few megabytes to tens of gigabytes of data need backup and recovery, but the cost of direct connection to a SAN is not justified. Network-based backup has become feasible for servers with larger volumes of data attached, primarily because of advancements in network speed and performance.
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Detailed information about the tests performed to characterize each of the potential throughput limitations and to optimize performance is provided later in the “Identifying solution limits, stress points, and optimal tuning” section. Overall results of the backup server characterization tests are summarized in the “Summary of test results” section at the end of this paper.
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Backup server configuration Both entry-class Integrity rx3600 and rx6600 servers running HP-UX 11i v3 Update 4 (Fusion 0903) were used as backup servers for this performance characterization effort.
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Additional test environment configuration details Additional components used in the test configuration shown in Figure 1 are: • HP StorageWorks Enterprise Systems Library (ESL) 712 E-series tape library • HP StorageWorks LTO-4 Ultrium 1840 FC tape devices (installed in the ESL 712e tape library) • HP StorageWorks 6000 Enterprise Virtual Array (EVA6000) Storage Subsystem • HP StorageWorks 4/256 Director FC Switch • HP StorageWorks 8/20q FC Switch • HP ProCurve Switch 3400cl with 10/100/1000-T port
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Overall testing found that the most optimal tuning combination for this particular backup server configuration was 32 buffers and 256KB I/O blocks. Figure 2 shows that two HP LTO-4 tape devices given the data mix used for this test effort can back up 450 MB/s total, or an average of 225 MB/s per LTO-4 tape device.
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One-gigabit Ether port limit testing To determine the maximum backup data I/O throughput that can be expected for each client over a single 1GbE NIC port, multiple backups cycles were performed, increasing the number of parallel backup data streams and, for each cycle, rerunning the tests with different backup utility tunable settings for the number of buffers and block size: first with 8 buffers and 64KB blocks, and then with 32 buffers and 256KB blocks. Figure 3 shows the results of these tests.
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HP StorageWorks Ultrium 1840 LTO-4 limit testing For optimal performance with tape devices, the most important contributing factor is providing data streaming continuously at the maximum throughput capacity of the device. If continuous data streaming to the tape device is not maintained, the device must stop media movement, reposition the media, and then restart the media when sufficient data is available to write to the media.
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combination for backup utility tunable settings is 32 buffers and 256KB I/O blocks. Again, because optimal tuning may vary from one backup server environment to another, similar tuning analysis should be performed for each specific environment. 4Gb FC HBA port limit testing Characterization and limit stress testing of the 4Gb FC port involved connecting tape devices in scaleup succession to a single 4Gb FC port until obtaining the maximum port throughput.
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Test results: implications for optimizing the test environment The results of the various limits, stress, and tuning tests described previously help define an optimal configuration for the network backup server test environment. The backup server configuration includes two 4Gb FC dual-port HBAs (four ports in total) and four HP LTO-4 tape devices. For maximum throughput in this configuration, the LTO-4 tape devices are connected so that each tape device has its own dedicated FC port.
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Figure 6: Data Protector backup server performance comparing rx3600 and rx6600 100 Total Data Throughput (MB/s) 700 600 80 500 400 60 300 40 rx6600 (8 CPU / 32 GB mem) rx3600 (4 CPU / 16 GB mem) rx6600 CPU% rx6600 Mem% 200 20 100 rx3600 CPU% 0 0 1 Tape 2 Tapes 3 Tapes 4 Tapes rx3600 Mem% The rx3600 server configuration has half the processors and memory of the rx6600 configuration.
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o One set of restores left the client file data in place and used the “No overwrite” option of Data Protector for the data restore operation (referred to hereafter as a “No Overwrite Restore”). A “No Overwrite Restore” restores only the missing files in a file system and retains existing files.
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restore performance. The results confirm that the I/O infrastructure and tape devices are no longer the limiting factors for restore operations. With the added overhead of writing to the file system and storage, restore throughput averages about one-third of the backup performance. Client server results While this performance characterization effort focuses mostly on the backup server, valuable information was collected on the client systems.
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Figure 8: Client backup statistics using Data Protector 120 100 80 60 CPU % Memory % 40 Backup MB/s 20 0 rx2600/2/2GB rx2600/2/4GB rx3600/4/8GB rx6600/2/4GB The graph in Figure 8 indicates that for backup operations, system memory is a greater limiting factor than CPU or storage connectivity type. The rx2600 system with 2 GB of memory was able to achieve only 106 MB/s of backup data throughput before being limited by memory (memory utilization reached 98%).
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The server with the most memory — the rx3600 client system with 8 GB of memory — has the highest data restore throughput performance.
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• Control interrupts (using the intctl command to manage interrupt configuration and handling) The newly re-architected Mass Storage Stack released with HP-UX 11i v3 delivers significant, new benefits for tuning I/O and displaying metrics, whether being used with a network backup server or for direct or SAN-based backup.
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ports or paths should be added to the system for greater throughput and efficiency. This characterization benefited immensely from the ability to capture client data read and write metrics for backup and restore operations on the client systems. The following is an example of sar –H command output. In addition to displaying the number of I/O operations per second (as does the sar –d command), the sar –H command displays more details about Reads and Writes. # sar -H 10 3 HP-UX hpsas002 B.11.
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tape devices by using scsimgr save_attr or scsimgr set_attr to manually set the tunable lpt_to_lockdown attribute to the desired lunpath to use for accessing the tape device. The settable lpt_to_lockdown attribute for tuning tape device access was introduced in HP-UX 11i v3 update 4 (Fusion 0903). The scsimgr get_attr command displays the current load balancing policy in effect and the associated I/O path that is locked down for a particular tape device.
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To verify the setting of the lunpath for the next use of the tape device /dev/rtape/tape12_BEST, reissue the scsimgr get_attr command as used in the first example of this section. This displays the lpt_lockdown and lpt_to_lockdown attributes for the device, as in the following example: # # scsimgr get_attr -D /dev/rtape/tape12_BEST -a lpt_lockdown -a lpt_to_lockdown SCSI ATTRIBUTES FOR LUN : /dev/rtape/tape12_BEST name = lpt_lockdown current = 0/7/0/0/0/1.0x500110a0008b9f73.
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Tape library and device considerations The HP StorageWorks ESL 712e tape library accommodates a variety of SAN topologies for configuration. For switched FC connections of tape devices to the backup server, use the management interface to ensure that the tape drive port settings are set to “Fabric” for each of the tape devices. In the test configuration, two tape devices were initially configured erroneously as “loop”, which negatively affected overall throughput to the device.
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Monitoring link utilization of APA When using a network link aggregation such as HP Auto Port Aggregation (APA), HP recommends initial monitoring of the network traffic on the physical links to ensure the network traffic is being balanced as expected. To display the inbound and outbound network traffic of individual network links, you can use tools such as Glance (-l option), the network switch management utility, or your selected performance measurement utility.
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Figure 10: Footprint of two rx3600s vs one rx6600 The smaller, yet very powerful rx3600 has a height of 4U EIA (Electronic Industries Association) units, while the rx6600 has a height of 7U. As shown in Table 1, the rx3600 delivers an amazing 517 MB/s (or 1.77 TB/hr) of network backup throughput with four LTO-4 tape drives. In contrast, the rx6600 can deliver 643 MB/s (or 2.2 TB/hr) of network backup throughput.
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and services that require faster backup and recovery, consider SAN-based backup made directly to tape devices on the SAN, Zero Downtime Backup (ZDB) solutions, and other possible methods available from HP. In particular, ZDB adds more flexibility to your enterprise data-center backup strategy and can help satisfy the needs of the most demanding of applications environments and services by fully offloading the backup overhead and data contention from your production environment.
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Table 2: Summary Performance metric or optimal configuration of configurations recommended for optimal performance Recommended, Notes optimal configuration Tuning combination (buffers and I/O block size) 32 buffers and 256KB I/O blocks for LTO-4 tape devices The 256KB I/O block size is recommended especially for systems that have the Online JFS product installed, as this block size implicitly enables the default setting for the Direct I/O feature of the file system, which improves backup performance.
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 Single, Persistent DSFs per device (SAN agility of Device Special Files using binding of LUN WWIDs)  Interrupt Control (management of interrupt configuration and handing with the intctl command) o When using a network link aggregation such as HP Auto Port Aggregation (APA), initially monitor the network traffic on the physical links to ensure the network traffic is being balanced as expected.
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The backup and restore functionality of these servers benefits immensely from the extensive tuning capabilities and I/O agility of HP-UX 11i v3. These capabilities, coupled with the unsurpassed level of reliability and robustness of Integrity servers, provides the best possible protection and recoverability of your business’ most important asset, your business-critical data.
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For more information For additional information and details about HP products and solutions discussed in this white paper, please visit the following web locations: • HP Integrity Servers: www.hp.com/products1/servers/integrity/index.html • HP-UX 11i v3: www.hp.com/go/HPUX11iv3 • HP-UX 11i v3 Mass Storage Stack Features: http://www.hp.com/go/hpux-core-docs (click on the HP-UX 11i v3 product link) • HP Data Protector: www.hp.com/go/DataProtector • HP Fibre Channel Host Bus Adapters: www.hp.
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© Copyright 2010 Hewlett-Packard Development Company, L.P. The information contained herein is subject to change without notice. The only warranties for HP products and services are set forth in the express warranty statements accompanying such products and services. Nothing herein should be construed as constituting an additional warranty. HP shall not be liable for technical or editorial errors or omissions contained herein. Trademark acknowledgments, if needed.