Technical white paper

Protecting enterprise servers with StoreOnce and CommVault Simpana HP StoreOnce Backup systems

Table of contents

Introduction 2

Technology overview 2

HP StoreOnce Backup systems key features and benefits 2

HP StoreOnce Backup systems in small to large data centers 3

Advantages of using StoreOnce Backup systems with CommVault Simpana 3 Comparison of NAS targets and Virtual Tape devices 4

HP StoreOnce Backup systems for Enterprise Server Backup using CommVault Simpana 4

CommVault Simpana backup infrastructure components 4 Capacity planning 5 Windows vs. Linux server CommVault Simpana backup deduplication ratios 6 Characteristics of CommVault Simpana backup schedule types to a StoreOnce Backup system 6 CommVault Simpana block size effect on throughput and deduplication ratio 9

Disaster recovery with local StoreOnce Backup system and remote replication 10

Recovery scenarios 11

Recommendations 12

Conclusion 12

For more information 13

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Introduction In today’s business environment, enterprise server customers rely on the most efficient, high performing, and reliable backup systems. Customers need to protect increasing levels of data while keeping costs under control. In particular, businesses today are concerned about the costs of backing up and archiving important data from mission-critical servers. HP StoreOnce Backup systems provide a disk-based data protection platform while addressing data growth by applying HP StoreOnce Deduplication software for efficient, longer term data retention.

This document describes the benefits of using HP StoreOnce Backup systems combined with CommVault Simpana to backup enterprise servers. This document also recommends backup and recovery implementations. Some of the key recommendations for CommVault Simpana backups to a StoreOnce Backup system:

• To improve backup storage utilization: backup one server at a time (sequentially) for quickly rising deduplication ratios that are maintained over time.

• To reduce backup windows: enable data multiplexing and configure multiple device streams to improve backup throughput performance while backing multiple servers simultaneously. The resulting interleaved backup data will cause a small decline in deduplication ratios.

• To increase backup speed without affecting deduplication ratios: use a larger CommVault Simpana backup block size for faster backup throughput performance with little or no effect on StoreOnce data deduplication ratios.

• To reduce the end-to-end data size: if the backup process can accommodate it, use a unique StoreOnce virtual tape library (VTL) or network-attached storage (NAS) share for each data type or same type of operating system.

• For the trade-off between backup impact and ease of recovery: configure a weekly full with daily incremental or initial full with daily incremental and synthetic full backup schedule to reduce the amount of end-to-end data and decrease the time required to run daily backups. StoreOnce Backup systems data deduplication will further reduce the end-to-end data size.

• For efficient and cost-effective movement of backup data offsite: use the StoreOnce remote replication feature along with CommVault Simpana replica disk library to seamlessly replicate all servers to an appliance in a remote facility for simpler recovery in the event of a disaster.

HP StoreOnce Backup systems are disk-based backup systems that deliver leading price-performance, and deduplicate server’s backup data. StoreOnce Backup systems coupled with CommVault Simpana can be used to automate and consolidate the backup of many physical servers onto a single, rack-mountable device while improving reliability by reducing errors caused by media handling.

For business environments with remote offices or a disaster recovery site, StoreOnce systems can be used to replicate data to a central data center or remote facility.

HP StoreOnce Backup systems are ideal for backing up mission-critical data from large enterprise servers. Proper configuration of CommVault Simpana and the HP StoreOnce Backup system provides better backup throughput performance and data deduplication ratios. StoreOnce Backup systems integrate into current IT environments and offer the flexibility of both VTL and NAS targets for enterprise server backups.

Technology overview

HP StoreOnce Backup systems key features and benefits • HP StoreOnce Deduplication, store more data on disk

HP StoreOnce Deduplication reduces the disk space required to store backup data sets without impacting backup performance. Retaining more backup data on disk for longer, enables greater data accessibility for rapid restore of lost or corrupt files and reduces downtime.

Deduplication ratios are strongly influenced by two factors—data change rate and backup data retention periods. Low data change rates and data retained for longer periods of time yield higher deduplication ratios.

• Deduplication-enabled replication

HP StoreOnce Deduplication is the technology enabler for HP StoreOnce Deduplication Enabled replication, which allows fully automated replication over low bandwidth links to a disaster recovery (DR) site, giving remote office/branch office (ROBO) and small data centers a cost effective DR solution for the first time.

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• Rapid restore of data for dependable, worry-free data protection

HP StoreOnce Backup systems offer immediate access to backups for rapid restores. StoreOnce Deduplication allows more data to be stored closer to the data center for longer periods of time, which offers immediate access for rapid restores.

• Automate, simplify, and improve the backup process

HP StoreOnce Backup systems automate your backup processes allowing you to reduce the time spent managing your data protection. Implementing hands-free, unattended daily backup is especially valuable for environments with limited IT resources, such as remote or branch offices.

StoreOnce systems can backup multiple servers via a standard Ethernet or Fibre Channel network simultaneously to a disk-based solution at peak speeds of up to 100 TB per hour instead of sequentially to a tape drive or autoloader, meaning that you can substantially reduce your backup window.

StoreOnce systems can be intuitively managed and configured by using the built-in Web browser’s administrative interface. For larger deployments of replicating StoreOnce appliances, the StoreOnce Replication Manager can monitor multiple backup systems across geographies. StoreOnce systems are self-managing backup appliances that require little, if any, routine maintenance. Unlike other disk-based storage devices, StoreOnce systems do not require virus protection or LUN provisioning.

HP StoreOnce Backup systems in small to large data centers

Advantages of using StoreOnce Backup systems with CommVault Simpana • Easier setup to protect, manage, and access data

• CommVault Simpana auto discovery technique provides a list of available StoreOnce Backup systems devices. This will be automatically made available for storage policy setup

• StoreOnce Backup systems data deduplication allows more backup data to be retained on disk for longer periods

• Use CommVault Simpana Vault tracker for managing and tracking the movement of media to and from an offsite storage facility

• Improve functionality, performance, and total cost of ownership while migrating data protection environments from disparate small systems into scalable StoreOnce Backup systems

• Easier to migrate traditional physical tape devices to StoreOnce Backup systems and perform workload balancing using CommVault Simpana migrate disk library capability

• Individual VTL/NAS devices can be configured in CommVault Simpana as separate libraries/disk devices for different purposes such as storage policy, auxiliary copy

• StoreOnce Backup systems with CommVault Simpana can be scaled out easily by adding MediaAgents and VTL/NAS backup devices

• Cross-platform migrations are easier, due to open tape format (OTF) of VTL devices when used with CommVault Simpana as target devices

• StoreOnce VTL/NAS devices can be configured with CommVault Simpana backup sets to serve specific operating systems. For instance, one VTL may serve RHEL and another for Windows®, and so on

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Comparison of NAS targets and Virtual Tape devices VTL and NAS configurations benefit from the same deduplication and replication features; however note the comparisons and recommendations in table 1.

Table 1. Comparison of NAS targets and Virtual Tape devices

VTL targets NAS targets

Recommended for customers looking to leverage their current investment in tape-based processes and software; easing migration using the same server based backup policies

Recommended for customers in non-tape environments, used to the simpler method of backup and recovery. HP recommends not using as general purpose NAS share

Appears to the backup application as physically connected tape devices, with backup and recovery jobs managed in the same manner

Seen by the backup server operating system, application, and users as a NAS share

Acts as a staging post to tape because backups are in tape format; supports tape offload using a backup application auxiliary copy feature

Enables use of backup application functionality that is only available with file shares, such as Disk-to-Disk-to-Tape implementations

Requires a backup application that supports backup to tape and media management

May be used with backup applications that do not support backup to tape

Integrates into the current backup routine and requires no special backup jobs

Requires a new backup job, but is simple to set up

May require purchase of a “tape backup” license for the backup application

Licensing is unique per backup application

HP StoreOnce Backup systems for Enterprise Server Backup using CommVault Simpana An important part of server administration is maintaining a consistent set of backup data, which should be available for recovery. When data is lost due to user error, system failure, or catastrophic site failure, there is a need for complete server recovery along with application data recovery. CommVault Simpana provides data protection software for multiple, heterogeneous servers, and operating systems. The backup data can be consolidated to a single StoreOnce Backup system leveraging Gigabit Ethernet, 10 Gigabit Ethernet, and Fibre Channel speed. StoreOnce Backup systems are optimized for sequential/simultaneous read/write operations. These provide a great fit with CommVault Simpana’s VTL/disk device abilities.

CommVault Simpana backup infrastructure components

Table 2. CommVault Simpana backup architecture

Component Description

CommServe server Communicates with all Clients and MediaAgents and co-ordinates all operations such as backup, restore, copies, media management and so on within a CommCell.

CommCell A CommCell consists of CommServe server, MediaAgents, and Clients.

CommCell GUI A graphical user interface that allows you to control and manage the operation of CommCell.

MediaAgent Manages the transmission of data between client and backup media.

Client A Client computer is any computer whose data must be backed up. The CommServe server and MediaAgent are also Clients.

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Figure 1 shows CommVault Simpana Backup architecture for enterprise servers with a StoreOnce Backup system.

Figure 1. CommVault Simpana Backup architecture with a StoreOnce Backup system

Capacity planning The required backup storage capacity for server backups depends on the following:

• Size of data and number of servers

• Backup retention policy (recovery points needed)

• Type (full, incremental, differential, or synthetic full) of backups

• Frequency of backups

• Rate of change of the data

• The deduplication ratio achieved by the StoreOnce Backup system

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HP StoreOnce Backup systems do not deduplicate across VTL or NAS shares. Each VTL and NAS share is an independent deduplication domain. To achieve better deduplication ratio a unique StoreOnce VTL or NAS share should be created specifically for similar data types. For larger environments, multiple VTL or NAS shares may work best with backups of similar type of operating system stored in the same VTLs or shares.

Note: The rate of change of the data refers to the amount of data that would be contained in an incremental backup as a percentage of a full backup. A 100 GB full backup with a subsequent 5 GB incremental backup before the next full backup would be a 5 percent rate of change.

An administrator may desire to have two weeks of backup stored on the StoreOnce system for quick recovery access.

Windows vs. Linux server CommVault Simpana backup deduplication ratios • RHEL servers tend to have a slightly higher deduplication ratio as compared to Windows servers for backup storage

devices such as NAS and VTL

• Deduplication ratios for NAS are slightly higher than VTL, irrespective of operating system

Figure 2 illustrates the deduplication ratio difference between RHEL and Windows operating system types. In performing these tests, HP used a standard customer representative dataset with realistic structure and content. For the chart below, data was updated between each backup until the desired rate of change was reached.

Figure 2. Windows vs. Linux server backup deduplication ratios

Characteristics of CommVault Simpana backup schedule types to a StoreOnce Backup system Many backup environments take advantage of CommVault Simpana’s different backup schedule types such as:

• Daily full

• Weekly full with daily incremental

• Initial full with daily incremental and synthetic full

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Expe

cted

ded

uplic

atio

n ra

tio

Number of full backups

CommVault backup deduplication ratio 5% rate of change

RHEL VTL

Windows NAS

RHEL NAS

Windows VTL

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Table 3 lists some characteristics of full/incremental/synthetic full backups to a StoreOnce Backup system over a period of 20 days with a 30 GB dataset.

Table 3. Comparison of different backup schedule types.

Daily full Weekly full/Daily incremental Synthetic full

Description Daily backup of all files Weekly backup of all files, daily backup of files that have changed since the last backup

Merge an initial full backup with all subsequent daily incremental backups to a point in time

Backed up data All data Weekly full—all data

Daily incremental—changed data since the last backup

Initial full—all data

Subsequent incremental—changed data since last backup

Synthetic full—merge of initial full and subsequent incremental backups

Relative backup time Long Short, except on days of full backup Short, except on days of full or synthetic full backup

Relative recovery time Short Long Short

Server load High Low, except on days of full backup Low, except on days of full or synthetic full backup

SAN/LAN bandwidth

requirement

High Low, except on days of full backup Low, except on days of full or synthetic full backup

Relative deduplication

ratio on appliance

High Low Low

Size on StoreOnce compared to non-deduplication

Small Very small Very small

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Figure 3 illustrates the end-to-end data compaction of full/incremental/synthetic full backups for 10 clients with 30 GB of data each to a StoreOnce Backup system over a period of 20 days.

Note: Data compaction refers to the removal of redundant information from a backup set prior to storing on a backup device. Incremental backups, deduplication, and compression are all methods for removing redundant data from a backup set.

Figure 3. Data compaction comparison of different backup schedule types

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CommVault Simpana block size effect on throughput and deduplication ratio CommVault Simpana supports varying block sizes for backing up server data. Larger block sizes usually result in better throughput and an increase in data deduplication ratios. HP recommends keeping the block size set at 256 and above for better throughput.

Figure 4. StoreOnce backup throughput benefits from higher block size.

Other factors affecting throughput:

• Chunk size: Chunk is unit of data that the MediaAgent uses to store data on media. This parameter will have an impact only when backing up to tape. A higher chunk size will give you better throughput.

• Data multiplexing: When multiple backups run in parallel to a single device, multiplexing results in better utilization of the device, which helps in better overall throughput and reduction of the backup window. With the help of multiplexing it is possible to backup multiple servers simultaneously.

• Maximum number of parallel data transfer operations: This feature allows you to set the maximum number of concurrent read/write operations to the MediaAgent. This value controls the maximum number of data streams that can be managed by the MediaAgent.

• Streams and data readers: A data stream can be thought of as a data channel that connects client file system to the storage media. Multiple streams are parallel channels through which data can flow, thus improving the rate at which data can be written to the storage media.

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Figure 5 illustrates StoreOnce Deduplication ratios when using different backup block sizes.

Figure 5. Varying block sizes vs. deduplication ratios

Other factors affecting deduplication ratio:

• Backup policies: Retaining data for longer period of time improves the chance that common data will already exist in storage, resulting in greater storage savings and better deduplication ratio.

• Compression/Encryption: Software compression and encryption prevents optimal deduplication from taking place. Since data that is already compressed and encrypted cannot be efficiently deduplicated.

• Data types: To improve deduplication ratio, configure individual VTL/NAS devices as separate library/disk devices in CommVault Simpana for individual server/type of operating system.

• Sequential backup: Backup one server at a time with network agent and number of data reader equal “1” to improve deduplication ratio.

Note: When CommVault Simpana is configured for simultaneous server backups to the same StoreOnce VTL or NAS share, it will result in interleaved backup data. Interleaving the data could cause a decrease in StoreOnce data deduplication ratios.

Disaster recovery with local StoreOnce Backup system and remote replication Most companies recognize the importance of a robust data protection strategy. Enterprise-level customers are likely to invest in local server’s recovery, as well as, site disaster recovery at remote site using replication. Many companies, large and small, are protecting servers in remote offices where untrained IT staffs are expected to manage a daily backup process—generally involving the changing of physical tapes, which is a process prone to more time consumption, resource draining, inefficient, and human error.

The combination of CommVault Simpana VTL/disk devices, replica disk library, alternate path for storage policy, and HP Low Bandwidth Replication (LBR), between StoreOnce Backup systems, offers the solution to these problems by allowing data to be replicated in a faster, reliable, automated manner. With CommVault Simpana auxiliary copy feature replicated data can be offloaded to tape devices. There is flexibility in doing data recovery, depending upon the situation or type of failure. For instance:

• Clients can be recovered at the StoreOnce source site (original client location).

• In the event of client source site disaster the target site StoreOnce can be shipped to source site or backup data can be replicated back to the source site for complete client recovery.

• Clients can be recovered at the StoreOnce target site using secondary path and replica disk library through remote MediaAgent (remote location).

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Recovery scenarios Figure 6 illustrates disaster recovery scenarios that may occur and the recovery path available when replicating between StoreOnce Backup systems.

Figure 6. Recovery scenarios

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Recommendations • Sequential vs. simultaneous server backup

– Backup one server at a time by disabling CommVault multiplexing and client side deduplication to achieve the best possible deduplication ratio.

– If backup throughput performance is the highest priority, use CommVault Simpana multiplexing to send multiple streams and use multiple data readers/writers for client to send multiple server backups simultaneously to the StoreOnce Backup system; however, the data will be interleaved on the StoreOnce system, resulting in a decline in the deduplication ratio.

• Backup block size

– Use a larger block size for improved backup throughput performance.

– The backup block size used by CommVault Simpana may have a small effect on data deduplication ratios on the StoreOnce Backup system.

• Daily full, weekly full with daily incremental or initial full with daily incremental, and synthetic full backup?

– Daily full backups deduplicate at a much higher rate than weekly full with daily incremental and synthetic full backups, but require more server and StoreOnce processing resources and SAN/LAN bandwidth.

– End-to-end data compaction is greater for incremental and synthetic full backup schedules over extended time, which means less storage space will be used on the StoreOnce Backup system.

• Disaster recovery

– StoreOnce remote replication offers a low bandwidth replication solution to and from remote sites, which is ideal for server disaster recovery.

– Server backups through CommVault Simpana to a StoreOnce pair configured with remote replication along with CommVault Simpana replica disk library and secondary path provides recovery for local disk failures, complete server failure or complete site failures by keeping server backup copies at local and remote sites.

Conclusion Enterprise server customers demand an efficient, reliable data growth management backup system environment while keeping costs under control. HP provides a variety of reliable data protection storage solutions that address such requirements. HP StoreOnce Backup systems along with CommVault Simpana is one such solution. StoreOnce Backup systems offer high performance and reliability, while addressing data growth through HP StoreOnce data deduplication technology. In addition, CommVault Simpana's unified data management solution brings together a full generation of traditional and next generation data protection from backup, to disk to replication management, to tape under one platform. In all, StoreOnce Backup systems integrate easily with CommVault Simpana to protect important data for mission-critical applications.

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For more information Address your requirements for an efficient, reliable, data-growth management backup system in an enterprise server environment, while keeping costs under control, by combining HP StoreOnce Backup systems with CommVault Simpana. To learn how, visit: hp.com/go/StoreOnce. HP StoreOnce Backup system user guide http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c02295179/c02295179.pdf

HP StoreOnce Backup systems Linux and UNIX® configuration guide http://h20000.www2.hp.com/bc/docs/support/SupportManual/c02299831/c02299831.pdf

HP D2D Backup systems best practices guide http://bizsupport2.austin.hp.com/bc/docs/support/SupportManual/c02511912/c02511912.pdf

CommVault Simpana backup and recovery documentation http://documentation.commvault.com

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© Copyright 2012 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.

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4AA4-3449ENW, Created October 2012