W H I T E P A P E R E n t e r p r i s e V T L s : S t r a t e g ic for Large-Scale Datacenters

W H I T E P A P E R E n t e r p r i s e V T L s : S t r a t e g ic for Large-Scale Datacenters Sponsored by: NetApp Laura DuBois December 2008 Robert Amatruda EXECUTIVE SUMMARY Global Headquarters: 5 Speen Street Framingham, MA 01701 USA P.508.872.8200 F.508.935.4015 www.idc.com Enterprise datacenters have built up extensive investments in large-scale tape infrastructures. Valuable corporate information resides there, and policies and processes have been developed to manage this infrastructure and its data. In largescale datacenters, it is impractical to envision physical tape infrastructures being eliminated. However, they are being augmented with other storage components such as virtual tape libraries (VTLs). IDC research finds the use of VTLs within the backup path can help firms address compressing backup windows and recovery times without disruption to an existing backup environment. Firms with large-scale tape silos and thousands of tapes must ensure the VTL they select offers the right level of performance, tape integration, and management features necessary to meet corporate service-level requirements for data protection. This paper outlines the key requirements these firms should use in assessing an enterprise VTL and evaluates the NetApp VTL against these requirements. SITUATION OVERVIEW Increasingly, within the datacenter, disk is being placed in the data protection path. Traditionally, backup data was sent directly to physical tape, but increasing growth of data has made it difficult for enterprises to complete backups successfully within shrinking backup windows using a tape-only strategy. Today, the increased use of disk relieves the backup bottleneck. Backup data now travels from disk to disk to tape to meet this challenge. Many firms are keeping up to 30 days of backup data on disk before migrating it to physical tape in order to meet more demanding recovery time requirements while also supporting the need for long-term retention or disaster recovery. The need for faster backups and restores to meet shrinking backup windows and shorter recovery times has spawned adoption of VTL technology. IDC research indicates that over the past several years, the drivers for investment in VTL solutions result from the need to:! Meet compressing backup windows without compromise! Provide faster restore and recovery times! Enable rapid integration with existing backup applications and policies! Improve performance and utilization of backup resources! Offer disaster recovery strategies that include offsite media

! Support physical tape for archive and regulatory requirements! Insert a logical integration point for the use of deduplication technology! Bring more efficiency to the use of tape media and libraries Despite claims that "tape is dead," most world-class datacenters point to ongoing investments in tape. In large part this is because tape is a very inexpensive medium for storing petabytes of data for disaster recovery and because it is more costeffective to continue using and scaling the tape asset they have already paid for rather than completely replace it with new infrastructure and media. In addition, most datacenters have human resources and IT processes that have been in place for years. VTL solutions enable an enterprise to protect its existing infrastructure, people, and processes without introducing unnecessary risk into the data protection environment. Moreover, corporate information and institutional knowledge resident in existing tape infrastructures can be preserved according to established local, offsite, and/or long-term retention requirements. Tape remains a critical part of the storage infrastructure due to its lower power/cooling requirements, removable nature, disaster recovery characteristics, and sound economic benefits. VTLs also extend the life of physical tape infrastructure. IDC's outlook for VTL technology calls for robust growth over the forecast period, with open system VTLs expected to account for nearly $1.2 billion of the worldwide VTL market in 2011 (see Figure 1). One key benefit of VTLs is they are designed to work with existing backup applications and do not require costly upgrades or replacement of backup software. Additionally, correctly implemented VTLs provide measurable increases in backup performance as well as improved recovery times. IDC data suggests key motivators for deploying VTLs vary by company size (see Table 1). Firms with 1,000 to 10,000 employees rely on VTLs for greater fault tolerance from physical tape failures and faster recovery. However, for larger firms (more than 10,000 employees) or firms managing over 1 petabyte of data, the key factor for deploying a VTL is reducing the backup window time by increasing backup performance, followed by improving reliability in both backups and restores. 2 #215573 2008 IDC

FIGURE 1 Worldwide Open Systems VTL Revenue, 2005 2011 1,200 1,000 800 ($M) 600 400 200 0 2005 2006 2007 2008 2009 2010 2011 Source: Worldwide Virtual Tape Library 2007 2011 Forecast and Analysis: Avenue of Growth (IDC #208326), August 2007 TABLE 1 Top Reasons for Using or Planning to Use a VTL by Size of Firm (% of Respondents) Q. What are the top two reasons your organization uses or plans to use virtual tape libraries? Total Large Firms (1,000 10,000 Employees) Very Large Firms (10,000+ Employees) Firms with over 1PB Eliminate or reduce backup window by improving 20.64 18.71 39.29 22.92 speed of backup Improve reliability of tape backup processes and 24.40 25.16 33.93 16.67 improve reliability of restore/recovery Improve recovery time from physical hardware, server 25.74 26.45 28.57 22.92 failure, or network error Reduce tape media and drive spending/costs 14.21 9.03 23.21 20.83 Improve recovery point from application, user, or 19.30 20.00 16.07 12.50 configuration error Improve recovery time from site disaster 21.45 22.58 14.29 27.08 Improve recovery point from physical hardware, 11.80 11.61 14.29 14.58 server failure, or network error Improve recovery time from application, user, or 21.72 26.45 10.71 14.58 configuration error Reduce data protection/administration overhead costs 9.92 8.39 10.71 14.58 Protect data at remote or branch office 18.50 18.71 8.93 18.75 Improve recovery point from site disaster 11.80 12.26 12.50 Other (specify) 0.54 0.65 2.08 Total n = 373 155 56 48 Source: IDC's Disk-Based Data Protection Survey, 2008 2008 IDC #215573 3

Enterprise VTL Feature Priorities Today, a myriad of different VTL solutions are available to large, enterprise-class customers. Firms must identify the core capabilities needed to alleviate backup performance bottlenecks and provide greater fault tolerance from physical tape failures. These issues are especially pressing for very large firms with more than 10,000 employees or managing more than 1 petabyte of data. More importantly, not all solutions are created equal. Many large VTL suppliers today share a common dependency upon the same developer of VTL software. These suppliers license the VTL intellectual property and then package a VTL with their existing storage systems. As a result, these suppliers have dependencies upon a third party for quality assurance, enhancements, new release features, and hardware qualifications. Level three services and support must also be shared among several major VTL suppliers. This could create unnecessary delays for new functionality and add risk to a VTL solution. IDC finds that the top four features influencing a firm's decision to purchase a VTL solution are tape integration, higher performance for backup/recovery, clustering for high availability, and single instancing to remove redundant data in the backup target. These top four purchasing factors are consistent across company size. However, larger firms with more than 10,000 employees or those managing over 1 petabyte of data place a higher emphasis on clustering for high availability as well as high performance throughput for retrievals during restores and recoveries. Because VTLs are strategic and complementary to tape infrastructure, enterprise firms with investments in tape automation and media must evaluate a VTL carefully to ensure adequate tape integration will give them the necessary support. Enterprise VTL Tape Integration Requirements Based on IDC research of the VTL market over the past three years, we recommend firms consider the following in selecting an enterprise-scale VTL:! Support offsite physical tape copy. A VTL must have the ability to export to physical tape in a catalog-consistent fashion. The backup application catalog must be aware of the physical tape copy, either the master tape or a tape clone. This tape can then be stored offsite for disaster recovery purposes. Some solutions rely upon backup software being installed within the VTL to achieve catalog consistency, which can increase cost and complexity significantly. Other solutions make use of published APIs, which is a cleaner, more standardized approach. A third option is to create a physical tape with the same barcode as the virtual tape and store it, which is a popular backup methodology approved by application providers.! Minimize backup load in physical tape support. When writing data from the virtual tape (disk) to physical tape, some VTLs require the media server to perform another backup, using additional media server memory and CPU cycles. In contrast, some solutions are able to support movement of backup data directly from the VTL disk to tape. 4 #215573 2008 IDC

! Provide high-performance backup to physical tape. With the largest backup loads, performance needs to be considered in terms of both sustained throughput to virtual tape and sustained MBps throughput to the physical tape target. Tape drives perform best when large sequential blocks are written to them. The VTL responsible for the movement of data between virtual and physical tape must ensure that this streaming occurs and that application or backup server bottlenecks when writing from VTL to physical tape do not cause tape drive "shoeshining," which can severely degrade tape drive performance. Other Enterprise VTL Requirements While tape integration is important for large-scale VTL deployments, it is not the only consideration. Other requirements include:! Storage optimization including deduplication. In the current economic climate and with data growth averaging 52% year over year, technologies that reduce the capacity required to store data as well as reduce power, cooling, and space requirements are becoming mandatory. VTL solutions should offer deduplication to achieve an initial set of economies, accompanied by fast (usually hardware accelerated) compression for another level of savings.! Security capabilities. Encryption of data over the wire (from the backup server to the VTL disk), at rest (in the VTL), and on physical tape should be supported. Many solutions offering deduplication do not yet offer encryption of data, and firms should be aware that encrypted data cannot be deduplicated. VTL solutions that offer native encryption should provide integration with external key management systems as well as shredding or data disposition features, rolebased access, and audit and monitoring.! Availability. Dual-node VTL architectures should offer high availability and automated failover of the backup stream into the VTL system from one node to the other. The backup should not fail because one of the VTL nodes goes down or loses network connectivity. Case Study: A Large Public Utility Large Public Utility Based in Western United States Critical Requirements for VTL Solution! Improve performance on restores! Reduce costs of physical tape handling and associated staff time! Eliminate offsite tape storage and collection services! Improve ease of deployment and management 2008 IDC #215573 5

Customer Profile This large public utility customer must support three in-state datacenters that connect to a collocation/disaster recovery facility. The company employs a tiered storage environment and Hitachi Data Systems (HDS) USP Systems for its tier 1 solutions and NetApp for its tier 2 and 3 storage. The company manages 30% of its total storage in its tier 1 infrastructure, which totals 90TB of raw storage and 60TB of usable storage. The company uses Shadow Copy to replicate its production data to the collocation facility for disaster recovery. Supported applications are Oracle and VMware. Furthermore, the company utilizes 256TB of raw capacity, which amounts to 154TB of usable storage for its tier 2 and 3 storage for desktop and file server applications. In its tier 2 and 3 storage layers, the company is using NetApp 6000 and 3000 systems with FC and NAS interfaces. The company replicates its tier 2 and 3 data to its collocation facility using SnapMirror. The company's server environment includes Unix and Windows systems, and approximately 70% of physical servers are virtualized using VMware and Sun Containers. The backup environment includes NetBackup and ESX Ranger for VMware backups to tier 3 NetApp disk filers, and virtual machine images are also replicated using Shadow Copy replication to the collocation facility. Currently, the company is using NetBackup with the following retention policies: Weekly full backups are saved for one year, and daily incremental backups are saved for six months. The company supports a legacy AS/400 system that recently was put on end of life. The company supports a large Sun/STK SL8500 tape library with over 1,800 tape cartridges and a mix of 28 LTO-2 and LTO-4 tape drives. In addition, the company supports two Sun/STK L180 tape libraries and an L700 library at separate facilities. Business Case for NetApp's VTL Three years ago, the company augmented its tape-based backup and disaster recovery infrastructure with a NetApp VTL 600. This was done to improve the performance of backups and to reduce the opex costs of handling and vaulting physical tape cartridges in offsite repositories. The company deployed a NetApp VTL 600 as an integral component of its collocation disaster recovery infrastructure. It expects to have the VTL 600 deployed in its current form for another one or two years. The company is using the NetApp VTL 600 as a target in the collocation facility performing backups over the high-speed OC-32 SONET connection. The company decision makers like the NetApp VTL solution due to its ease of implementation (up and running in less than one hour) and simplistic Web-based management interface. The Bottom Line As a result of deploying the NetApp VTL 600, the company gained measurable benefits in its operational costs associated with its backup and disaster recovery infrastructure. Those benefits include:! Recapturing a half of an IT administrator's time spent on tape handling procedures, which is estimated to be $45,000 assuming a $90,000 fully compensated administrator 6 #215573 2008 IDC

! Eliminating a significant portion of the offsite tape storage and collection services from the reduction of physical tape cartridges in rotation! Reducing expenditures for tape cartridges from $160,000 to $200,000 on an annual basis to an estimated $60,000 a year cutting tape costs by more than half! Reducing restore times to hours, not days, using VTL and Shadow Copy with no physical tape being handled, mounted, or read The customer will still support physical tape for sometime it will not go away completely. Tape will be used primarily for consumption history for seven-year retention policies for financial records. That said, the company will still invest in its VTL infrastructure for the foreseeable future. The NetApp VTL solution provided measurable benefits to the company's operational expenditures with regard to staff time, physical tape media, offsite vaulting, and ease of deployment. In fact, the company manager who oversaw the Net App VTL 600 deployment said, "It was so easy a caveman can do it." NETAPP VTL Overview With 100% NetApp technology ownership, the NetApp VTL family provides performance, scalability, and ease of use. Certified with all leading backup applications, NetApp's VTL solutions are purpose built and tuned for backup and recovery, providing the throughput needed to meet tightening backup and restore windows. With features such as write aggregation and high-speed hardwareaccelerated compression, NetApp VTL delivers up to 8.2TB/hr of throughput, enabling a firm's backups to complete on time. And for physical tape creation, NetApp VTL has an embedded tape path providing up to 3.0TB/hr so that tapes can easily be sent offsite for disaster recovery. The NetApp VTL systems have a single operating system that runs the tape emulation feature and provides integrated disk management. NetApp VTL offers three models for a range of capacity, performance, and price requirements (see Table 2). 2008 IDC #215573 7

TABLE 2 NetApp VTL Series Overview VTL 300 VTL 700 VTL 1400 Max Usable Capacity (Uncompressed)* 55TB 275TB 550TB Max Virtual Capacity (@20:1) 1PB 5PB 10PB Max Sustained Throughput (TB/hr)* Deduplication running 1.5 2.1 4.3 Standard compression 2.3 4.1 8.2 Direct Tape Creation Speed (TB/hr)* 0.9 1.5 3.0 Note: * Max performance and capacity are calculated using Base 10 arithmetic. Standard compression assumes deduplication is not running on a specific virtual library and data compression of 2:1. Source: NetApp, 2008 NetApp VTL Feature/Functions As shown in Table 2, the NetApp VTL has published single controller throughput of 1,150MBps with 2:1 hardware compression. In addition to its performance capabilities, the solution has some enterprise-level functions not available with other solutions on the market today. One unique feature is the Direct Tape Creation capability. This feature allows highspeed movement of backup data directly to tape from the VTL without bringing it back through the backup media server or storage node. This enables faster creation of physical tapes for disaster recovery and eliminates overhead on the backup server and network. The NetApp VTL maintains a 1:1 relationship between the virtual tape and the physical tape, and when the backup application issues an eject tape command to the VTL, this will create a physical tape copy in the tape library and eject it through the tape library entry/exit port. Direct Tape Creation is often coupled with Tape Smart Sizing, a feature that evaluates the compressibility of a backup stream and dynamically adjusts the size of the virtual tape to improve media utilization by packing as much data as possible on a tape. In addition, the NetApp VTL can maintain a hidden copy on disk, called a Shadow Copy, which is automatically accessible to the backup application for restores. The Shadow Tape pool acts as a cache that stores hidden copies of tapes on the VTL, and upon a restore request where the physical tape has already been ejected and sent offsite, the backup application will instruct the VTL to retrieve the data from the shadow pool versus physical tape. This improves restore times by eliminating the need to find, load, and then access a physical tape that may be hours away at an offsite facility. NetApp VTL offers native block-level deduplication as part of its core VTL operating system, which stores only unique data, reducing disk capacity for storing backups up to 95%. For deduplication, the system uses a rolling hash algorithm in combination with sequential byte-level comparison for improved data integrity over a hash-only comparison approach. 8 #215573 2008 IDC

The NetApp VTL is a single integrated solution. The single NetApp VTL disk controller runs the VTL tape emulation software and the integrated deduplication functionality that are both part of a single VTL operating system owned and developed by NetApp. Also running on the NetApp disk controller are disk management capabilities for easy RAID group creation that can be done by a non Fibre Channel storage person. Making use of this internal RAID group creation wizard, no disk formatting process is required. When additional RAID groups are created, they become immediately available via dynamic load balancing, and no scheduling or rebalancing of the storage is necessary. With the controller, software, and disk all owned by NetApp, this eliminates any finger-pointing in a service escalation situation and enables immediate escalation within a single service organization. CHALLENGES The key challenges that NetApp will encounter with its VTL will be communicating the strong value proposition that its VTL solution brings not only to its current customers but also to new customers. NetApp's support of physical tape is critical and necessary, especially for large customers. In addition, NetApp must be focused on displacing well-entrenched incumbent VTL suppliers. Not an easy task. Many of NetApp's competitors not only are well versed in and support physical tape but also sell an enormous amount of tape with their VTL solutions. Another challenge NetApp (and other suppliers must address) is the customer requirement to have data protection appliances that can serve as the target for multiple different data protection workloads, replication, virtual tape, archiving, and the like. Lastly, deduplication will be a core requirement for all of these workloads, and block-level deduplication must eliminate redundant data across these workloads. NetApp is making great strides with enhancements to its VTL to be part of a holistic protection and recovery framework. Longer term, the industry needs to eliminate these separate physical and logical islands. However, the NetApp VTL is still a separate appliance in addition to other disk-based data protection approaches and systems. CONCLUSION In summary, enterprise datacenters are placing disk in the data protection path with the insertion of VTLs. Large datacenters will continue to invest in VTL technology to augment existing tape infrastructure and processes. Large and very large firms should evaluate VTL solutions with strong tape integration features, efficiency gains through deduplication, and superior performance characteristics to deal with enterprise-level capacity and throughput requirements, today and in the future. Copyright Notice External Publication of IDC Information and Data Any IDC information that is to be used in advertising, press releases, or promotional materials requires prior written approval from the appropriate IDC Vice President or Country Manager. A draft of the proposed document should accompany any such request. IDC reserves the right to deny approval of external usage for any reason. Copyright 2008 IDC. Reproduction without written permission is completely forbidden. 2008 IDC #215573 9