Technical white paper

Protecting enterprise servers with StoreOnce and NetWorker 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 EMC NetWorker 3 Comparison of NAS targets and virtual tape devices 4

HP StoreOnce Backup systems for enterprise server backup using EMC NetWorker 4

EMC NetWorker backup infrastructure components 5 Capacity planning 6 Windows vs. Linux server EMC NetWorker backup deduplication ratios 6 Characteristics of EMC NetWorker’s backup schedule types to a StoreOnce Backup system 7 EMC NetWorker block size effect on throughput and dedup ratio 8

Disaster recovery with local StoreOnce Backup system and remote replication 10

Recovery scenarios 10

Recommendations 11

Conclusion 12

For more information 12

2

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 EMC NetWorker to backup enterprise servers. This document also recommends backup and recovery implementations. Some of the key recommendations for EMC NetWorker 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: backup multiple servers simultaneously through server parallelism to improve backup throughput performance. The resulting interleaved backup data will cause a small decline in deduplication ratios.

• To increase backup speed without affecting deduplication ratios: use a larger EMC NetWorker 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 consolidated 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 EMC NetWorker’s staging and cloning 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 a disk-based backup system that delivers leading price-performance, and deduplicates server’s backup data. StoreOnce Backup systems coupled with EMC NetWorker 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 EMC NetWorker 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.

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• 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.

• 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 EMC NetWorker • Makes it easier for setup and maintenance

• Allows more backup data to be retained on disk for longer periods, due to using StoreOnce Backup systems data deduplication

• Improves functionality, performance, and total cost of ownership while migrating data protection environments

• Makes it possible to consolidation disparate small systems into scalable StoreOnce Backup systems

• Makes it easier to migrate traditional physical tape devices to the StoreOnce Backup systems using EMC NetWorker’s staging and cloning capability.

• Easier to manage since individual VTL/NAS devices can be configured in EMC NetWorker as separate pools for different purposes such as staging, cloning and archiving

• Easily scaled out by adding storage nodes and VTL/NAS backup devices onto StoreOnce Backup systems with EMC NetWorker

• Easier to perform Cross-platform migrations, due to open tape format (OTF) of VTL devices when used with EMC NetWorker as target devices

• StoreOnce VTL/NAS devices can be configured with EMC NetWorker in such way to serve specific operating systems. For instance, one VTL may serve RHEL, and another for Windows®, and so on

• Makes it practical to perform regular snapshots with StoreOnce NAS backup devices

• Easily offload StoreOnce Systems backup data to a traditional tape drive system for offsite archiving at a remote/disaster recovery site

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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 VTL 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 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 EMC NetWorker 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. EMC NetWorker 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 and Fibre Channel speed. StoreOnce Backup systems are optimized for sequential/simultaneous read/write operations. These provide a great fit with EMC NetWorker’s advanced file type/VTL device abilities.

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EMC NetWorker backup infrastructure components Table 2. EMC NetWorker backup architecture components

Component Description

Console server All EMC NetWorker servers and clients are managed from the NetWorker Console server. The Console server also provides reporting and monitoring capabilities for the servers and clients.

Web browser The Console server is accessed through a graphical interface that can be run from any computer that has a Web browser. Multiple users can access the Console server concurrently from different browser sessions. A computer that hosts the Web browser can also be a NetWorker client.

NetWorker server NetWorker servers provide services to back up and recover data for the NetWorker client computers in a datazone.

Datazone A datazone is a single NetWorker server and its client computers. Datazones can be added as backup requirements increase.

NetWorker storage node A NetWorker storage node can be used to improve performance by offloading much of the data movement from the NetWorker server involved in a backup or recovery operation.

NetWorker client A NetWorker client computer is any computer whose data must be backed up. The NetWorker Console server, NetWorker servers, and NetWorker storage nodes are also NetWorker clients.

Figure 1 shows EMC NetWorker backup architecture for enterprise servers with a StoreOnce Backup system.

Figure 1. EMC NetWorker backup architecture with a StoreOnce Backup system

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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, level 1–9, or consolidated) of backups

• Frequency of backups

• Rate of change of the data

• The deduplication ratio achieved by the StoreOnce Backup system

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

Note: The rate of change of a 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. In performing these tests, HP used a standard customer representative dataset with realistic structure and content.

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

Windows vs. Linux server EMC NetWorker backup deduplication ratios • RHEL servers tend to have a slightly higher dedup ratio as compared to Windows servers for backup storage devices

such as NAS and VTL.

• Dedup 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.

Figure 2. Windows vs. Linux server backup deduplication ratios

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

• Daily full

• Weekly full with daily incremental

• Initial full with daily incremental and bi-weekly consolidated

Table 3 lists some characteristics of full/incremental/consolidated backups to a StoreOnce Backup system over a period of 15 days with a 30 GB dataset.

Table 3. Comparison of different backup schedule types

Daily full Weekly full/Daily incremental Consolidated

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

Consolidated—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 consolidated backup

Relative recovery time Short Long Short

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

SAN/LAN bandwidth

requirement

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

Relative dedup ratio on appliance

High Low Low

Size on StoreOnce compared to non-dedup

Small Very small Very small

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Figure 3 illustrates the end-to-end data compaction of full/incremental/consolidated backups for 10 clients with 30 GB of data each to a StoreOnce Backup system over a period of 15 days.

Figure 3. Data compaction comparison of different backup schedule types

EMC NetWorker block size effect on throughput and dedup ratio EMC NetWorker supports varying block sizes for backing up server data. It is possible to backup multiple servers simultaneously. 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 illustrates how StoreOnce Backup throughput benefits from higher block size.

Figure 4. Varying block sizes vs. backup throughput

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Other factors affecting throughput:

• NetWorker Parallelism

– A save set is a set of files or file systems defined for backup.

– Client parallelism determines how many save sets a client can send simultaneously in a backup.

– Server parallelism determines how many save sets a server will allow to be active simultaneously.

– Save group parallelism determines how many backup save sets may be active simultaneously in a group.

– When backing up data to StoreOnce Backup systems VTL/NAS shares, increase parallelism to improve backup throughput performance.

• Max active devices: In order to have a storage node fully optimize all the devices in the media library, set the max active devices attribute to number of devices available.

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

Figure 5. Varying block sizes vs. dedup ratios

Other factors affecting dedup 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 dedup ratio.

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

• Data types: To improve dedup ratio, configure individual VTL/NAS devices as separate storage pools in EMC NetWorker for individual server/type of operating system.

• Sequential backup: Backup one server at a time with client and server parallelism equal “1” to improve dedup ratio.

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

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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 human error.

The combination of EMC NetWorker advanced file type devices/VTL 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 EMC NetWorker cloning or staging, 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 a client source site disaster, the target site StoreOnce can be shipped to the source site or the backup data can be replicated back to the source site for complete client recovery.

• Clients can be recovered at the StoreOnce target site (remote location).

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 NetWorker parallelism to achieve the best possible deduplication ratio.

– If backup throughput performance is the highest priority, use EMC NetWorker parallelism to multiplex savesets and clients 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 EMC NetWorker 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 consolidated backup?

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

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

– If the fast recovery made possible by daily full backups is not required, and obtaining the highest possible dedup ratio is not the priority, HP recommends a backup schedule that includes incremental backups or incremental backups with weekly/Bi-weekly consolidated backups.

• 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 EMC NetWorker to a StoreOnce pair configured with remote replication provides recovery for local disk failures, complete server failure or complete site failures by keeping server backup copies at local and remote sites.

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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 EMC NetWorker is one such solution. StoreOnce Backup systems offer high performance and reliability, while addressing data growth through HP StoreOnce data deduplication technology. In addition, EMC NetWorker brings together a full generation of traditional and next generation data protection from backup, to disk to replication management, to tape under a unified interface. In all, StoreOnce Backup systems integrate easily with EMC NetWorker to protect important data for mission-critical applications.

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 EMC NetWorker. 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 StoreOnce Backup systems best practices guide http://bizsupport2.austin.hp.com/bc/docs/support/SupportManual/c02511912/c02511912.pdf

EMC NetWorker backup and recovery admin/user guide emc.com/networker

Get connected hp.com/go/getconnected

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4AA0-8901ENW, Created July 2012