NETAPP TECHNICAL REPORT
NearStore® VTL Integration with Symantec® NetBackup™
Chuck Dufresne, Network Appliance, Inc. May 2007 | TR-3576
SYM ANTEC AND NETAPP P AR TNERSHI P
Symantec and NetApp are committed to meeting the challenges faced by enterprise storage customers with a variety of elegant, cost-effective solutions. The tight integration between NetApp storage solutions and Symantec world-class software solutions enables enterprises to get the best solutions for consolidation of disparate resources, data recovery availability, and management. When used together, the solutions from both companies provide unique capabilities not available with any other product set. By leveraging the strengths of NetApp and Symantec, enterprises gain the ability to solve the most difficult storage problems with simplicity.
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TABLE OF CONTENTS
1 NEARSTORE VTL WITH SYMANTEC NETBACKUP............................................................... 4
1.1 INTENDED AUDIENCE ............................................................................................................................................. 4 1.2 PURPOSE ................................................................................................................................................................. 4 1.3 INTRODUCTION ....................................................................................................................................................... 4
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EXECUTIVE SUMMARY ............................................................................................................ 4
2.1 ENTERPRISE DATA PROTECTION CHALLENGES................................................................................................. 4 2.2 THE NETBACKUP AND NEARSTORE VTL SOLUTION........................................................................................... 5
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NEARSTORE VTL FEATURES AND FUNCTIONALITY .......................................................... 5
3.1 HARDWARE-BASED DISK COMPRESSION............................................................................................................ 5 3.2 CONTINUOUS SELF-TUNING .................................................................................................................................. 6 3.3 DIRECT TAPE CREATION........................................................................................................................................ 7 3.4 VIRTUAL TAPE SMART SIZING............................................................................................................................... 7 3.5 SHADOW TAPES...................................................................................................................................................... 8 3.6 SMART FILE RESTORES ......................................................................................................................................... 8 3.7 SEAMLESS AND EASY INTEGRATION ................................................................................................................... 8 3.8 RAID-VTL/JOURNALED OBJECT STORE ............................................................................................................... 9 3.9 ADDITIONAL FEATURES....................................................................................................................................... 10 3.10 NETAPP TECHNOLOGY: 100% OWNERSHIP ....................................................................................................... 11 3.11 DECRU® DATA ENCRYPTION (OPTIONAL).......................................................................................................... 11
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NEARSTORE VTL: INTEGRATION WITH NETBACKUP ....................................................... 11
4.1 IMPORTANCE OF CREATING PHYSICAL TAPE ................................................................................................... 11 4.2 PHYSICAL TAPE CREATION METHODS............................................................................................................... 11 4.3 USING NETBACKUP TO CREATE PHYSICAL TAPE COPIES .............................................................................. 12 4.4 USING NEARSTORE VTL DIRECT TAPE CREATION............................................................................................ 12 4.5 DIRECT TAPE CREATION/SHADOW TAPES: BENEFITS ..................................................................................... 14
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CONCLUSION .......................................................................................................................... 16 REFERENCES.......................................................................................................................... 16
6.1 NETAPP NEARSTORE VIRTUAL TAPE LIBRARY PRODUCT PAGE.................................................................... 16 6.2 SYMANTEC HARDWARE COMPATIBILITY LISTS FOR NETBACKUP ................................................................. 16 6.3 SYMANTEC NETBACKUP PRODUCT PAGE......................................................................................................... 16 6.4 VERITEST NETWORK APPLIANCE NEARSTORE VTL600 AND EMC CLARIION DL710 PERFORMANCE COMPARISON ................................................................................................................................................................ 17 6.5 NEW TAPE DRIVE TECHNOLOGY ARTICLE BY CURTIS PRESTON ................................................................... 17
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LISTING OF FIGURES
Figure 1) NearStore VTL Conceptual Diagram ............................................................................................... 5 Figure 2) Maximum primary storage protected during a backup window with compression enabled (two-toone data set) ................................................................................................................................................... 6 Figure 3) NearStore VTL GUI ......................................................................................................................... 9 Figure 4) NearStore VTL automatic RAID configuration ............................................................................... 10 Figure 5) Physical tape creation methods conceptual diagram..................................................................... 12 Figure 6) Optimized tape utilization with Smart Sizing .................................................................................. 13 Figure 7) Performance benefits of direct tape creation chart ........................................................................ 15
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NEARSTORE VTL WITH SYM ANTEC NETBACKUP
1.1 INTENDED AUDI ENCE
This document is intended for NetApp NearStore VTL and Symantec VERITAS™ NetBackup users. The audience is expected to have a working knowledge of tape-centric backup applications in general. It is helpful to have a working knowledge of NetBackup.
1.2 PURPOSE
The intended purpose of this guide is to assist NearStore VTL and NetBackup users in understanding how NearStore VTL integrates with and adds value to NetBackup data protection environments so as to deliver the full business benefits of the combined solution.
1.3 INTRODUCTION
The NearStore VTL is a high-performance, disk-based storage appliance that emulates physical tape libraries and tape drives. It dramatically improves existing backup environments by increasing the performance and reliability of backup and restore operations, reducing media costs and simplifying backup management. Section 3 of this document covers features of the NearStore VTL solution. Section 4 focuses on NearStore VTL integration with NetBackup and the specific options for creating physical tape copies.
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EXECUTIVE SUMMARY
2.1 ENTERPRI SE D AT A PRO TECTION CH ALLENGES
Today’s backup administrator is faced with a variety of challenges • • Explosive data growth: The proliferation of data has created challenges for legacy, tape-centric backup environments. Shrinking backup windows: 24x7 availability has evaporated backup windows, and the mechanical handling of tape media has exacerbated maintenance headaches as more demand is placed on overtaxed tape infrastructures. Backups take too long: While many new tape drives are capable of writing at high speeds, they require data to be streamed at high speed from the source. Failure to maintain high-speed streams results in the drives being underutilized because of tape drive back-hitching (shoe-shining). Extensive use of multiplexing is typically needed to keep the drives streaming, but this results in greatly reduced recovery performance. Recoveries take too long: Recovery from tape involves mechanical handling of media, load and seek time, in additional to data transfer time. If backup images are multiplexed to tape the data transfer rate would be inversely proportional to the number of multiplexed backup streams. Multiple restores exacerbate the problem of sequentially accessed media. Backups/restores are unreliable: Mechanical handling of tapes is a major cause of backup failures. When tapes get stuck in tape drives in the middle of the night, backups fail, creating compliance concerns in addition to the operational costs associated with determining what action to take. Did the tape drive just need cleaning? Is there a piece of media that has gone bad? Should the tape drive be replaced? When backups become unreliable, the ability to restore is affected.
•
•
•
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•
Media management: The sheer volume of tapes and the hours required to manage those tapes are costly and complex. As data continues to grow, the costs associated with managing tape media also increase.
Upgrading to the next generation of tape drive technology may not be the answer to some of these problems because of past investments made in tape media; new tape drives are typically backward-write-compatible for only one generation (LTO-3 drives cannot write to LTO-1 media). Additionally, newer tape drives are typically harder to keep streaming (LTO-3’s Digital Speed Matching [DSM] requires 40MB/sec minimum to keep the tape from shoe-shining).
2.2
THE NETB ACKUP AND NE ARSTO RE VTL SOLUTION
The combination of NetBackup and NearStore VTL brings performance, reliability and usability into the data center. NearStore VTL complements NetBackup to better utilize and enhance legacy investments in tape hardware and media. NearStore VTL does not replace tape but extends its useful life by providing a high-speed cache to eliminate shoe-shining during the backup window and provides efficient write performance when generating physical tape. Reliability is enhanced by removing the mechanical handling of physical tape outside the backup window. Fast restore performance is achieved by keeping more recent backups on disk with older images automatically archiving to tape.
Figure 1) NearStore VTL Conceptual Diagram
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3.1
NEARSTORE VTL FEATURES AND FUNCTIONALITY
H ARDW ARE- B ASED DISK COMPRESSI ON
High-performance data compression substantially increases backup and recovery service levels by doubling to tripling the amount of backup data that can be stored on disk, while also significantly increasing VTL write performance. NearStore VTL systems are unique in achieving these cost savings without sacrificing the performance required to meet backup windows in enterprise data centers. With compression enabled, the VTL700 delivers sustained write performance of 950 MB/sec, using data sets compressible at two-to-one, the equivalent of over 4TB per hour for a single controller system. In addition, NearStore VTL systems can achieve even higher performance levels if backup data is compressible at ratios beyond two-to-one.
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90.0 80.0 Primary Storage (TB) 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 4 8 12 16 Backup Window (hours) 20 24
NearStore VTL700
EMC DL4100
Figure 2) Maximum primary storage protected during a backup window with compression enabled (two-to-one data set)
Sources: NetApp NearStore VTL Technical Specifications, and EMC Backup-to-Disk for Open Systems Practitioner’s Guide, November 2006.
Example: NearStore VTL can back up 29TB in eight hours. VTLs that use softwarebased compression can only back up 9TB in the same backup window.
3.2
CONTINUOUS SELF-TUNI NG 1
The NearStore VTL continuously balances backup streams across available disk resources to deliver optimal performance for all storage capacities and backup application workloads: no manual tuning is required. As data loads change, backup streams are automatically directed to the least loaded disks. If additional capacity is added, the NearStore VTL will automatically allocate I/O across the new disks to achieve the best possible performance. The NearStore VTL can also instantly adjust to the variable data transfer rates of typical backup streams without sacrificing performance. Unlike tape drives, the NearStore VTL does not require data to be written within specific throughput ranges to achieve optimal performance; the NearStore VTL writes each backup stream at the maximum rate it can be delivered by most enterprise-class backup servers.
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Source: VeriTest Network Appliance™ NearStore VTL600 and EMC CLARiiON DL710 Performance Comparison (see References section 6.4).
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3.3
DIRECT TAPE CREATIO N
The NearStore VTL provides several workflow options for copying backup data from virtual to physical media, and each option is fully compatible with NetBackup media manager software. This means that physical tapes can always be located and retrieved, whether they are stored in a library or moved to an off-site location. The highest backup performance is achieved when the NearStore VTL is used to copy backup images stored on disk directly to a physical tape library. This tape creation option replaces the much slower method of using the NetBackup server to perform the copy-totape operation. The NearStore VTL offloads this chore from the NetBackup server and reduces storage network traffic by writing directly to tape over high-speed Fibre Channel. By writing to tape in efficient, high-speed streaming mode, this method can actually increase the useful life of both tape drives and media since they are not subjected to constant “back-hitching / shoe-shining.” Users have the option of creating tape copies immediately following a backup, during a specified time frame outside of the backup window, or whenever NetBackup issues an eject command. It is also possible to retain virtual tapes in the NearStore VTL (subject to customer retention policies) even after the physical copy has been removed from the tape library. This workflow option provides the protection of off-site storage and the benefits of high-speed disk restores. Users still have the option of using the backup server to process all of the copy-to-tape operations. However, this option is slower than using the NearStore VTL to create tapes and does not fully utilize the inherent performance benefits of disk-based backups. For all of the options described above, the physical tapes are written in 100% native NetBackup format. This means any physical tape, which has been generated by the NearStore VTL, can be restored by a NetBackup server from any physical tape drive configured as the same media/drive type as the virtual media/drive type in the VTL. It is not necessary to provide a NearStore VTL at the disaster recovery site.
3.4
VIRTU AL TAPE SM ART SIZING 2
NearStore VTL Virtual Tape Smart Sizing reduces media usage by 50% compared with other VTLs. As backup streams are written to virtual tape, the NearStore VTL monitors the compressibility of each stream and dynamically adjusts the size of each virtual tape to match the compressed capacity of the physical tape. This ensures that the physical tape will be optimally utilized, regardless of the type of data and its compressibility. And because NearStore VTL determines compressibility through statistical sampling, there is no noticeable impact to backup performance. Tape Smart Sizing is based upon the fact that all data compresses differently; the actual amount of data that will fit onto a given physical tape cartridge varies from backup to backup. In addition, there must be a one-to-one relationship between each virtual tape and its physical counterpart in order to maintain full compatibility with the backup software. As a result, the only way to fully utilize the physical tape media is to intelligently size each virtual tape prior to tape drive compression. Other VTL vendors do not take tape drive compression into account and require that each virtual tape be statically sized to the native capacity of the corresponding physical tape cartridge (for example, 200GB for an LTO-2 drive). Since physical tape drives will compress data at a two-to-one ratio on average, this means that competing VTL solutions will only fill approximately half of each physical tape cartridge, which means that twice the
Source: VeriTest Network Appliance NearStore VTL600 and EMC CLARiiON DL710 Performance Comparison (see References, section 6.4).
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number of physical tapes must be purchased and managed compared with the NearStore VTL.
3.5
SH ADOW TAPES
Shadow tapes provide the ability to create physical tape copies for off-site storage while keeping data on disk for instant restores, and they do so in a manner that is 100% compatible with all backup application software, including NetBackup. Shadow tapes enable instant restores from NearStore VTL by automatically caching exported tapes, so that a hidden copy of a virtual tape can remain on disk even after the backup data has been exported to physical tape media. Shadow tapes are 100% compatible with NetBackup because they allow NetBackup to perform the media management and location tracking for the physical tape copies, while the NearStore VTL performs the space management and tracking of the disk-resident shadow tapes. Shadow tapes can be retained on disk indefinitely, subject to the availability of free space in the NearStore VTL. The NearStore VTL manages the amount of space used by the shadow tapes and automatically frees up space to store new backup data as needed. NearStore VTL with shadow tapes enables storage administrators to meet two competing requirements in a way that is fully compatible with their existing backup software: (1) meet service level agreements for creating physical copies that must be moved off-site for safe storage within a specified time frame and (2) meet user demands to quickly restore backup data, typically from the relatively recent past, without having to recall a tape from off-site storage. Unlike other VTLs, the NearStore VTL shadow tape feature does not require end users to manually manage the backup process in order to achieve the goal of fast off-site tape creation and rapid restores. Only NearStore VTL provides policy-based retention and expiration of disk copies to provide the benefits of D2D backups without the expense of increased IT management.
3.6
SM ART FILE RESTORES
The NearStore VTL includes an automated pass-through mechanism that allows extremely fast restores when the data needed is on physical tape. When a physical tape is selected for import, the NearStore VTL immediately makes the tape available as a virtual tape while the physical tape is being imported into the VTL in the background. If NetBackup requests data that has not yet been copied in, the NearStore VTL switches into pass-through mode. This immediately repositions the physical tape to the point from which data is being requested and makes the data available to NetBackup as it buffers it to disk for performance. The NearStore VTL will later read in any data that was skipped over during pass-through. This facilitates extremely fast restores without the need to copy an entire physical tape before accessing data.
3.7
SE AM LESS AND E ASY INTEGR ATION
The intuitive, workflow-based GUI and RAID-VTL make deployment and administration of NearStore VTL easy. Data protection administrators easily adapt to a workflow and a paradigm that are familiar and intuitive, as opposed to making a substantial intellectual investment in storage management administration skills.
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Figure 3) NearStore VTL GUI
3.8
R AID- VTL/ JOURN ALED OBJECT STO RE
The NearStore VTL utilizes a highly optimized disk format called the Journaled Object Store (JOS) for storing backup data to disk in the form of virtual tape cartridges. This disk format requires no management and is designed to deliver the highest levels of performance for the sequential workloads generated by backup applications such as NetBackup. The JOS data store is also tightly integrated with a unique RAID data protection system called RAID-VTL, which is also geared toward providing optimal performance and failure resiliency in the context of backup workloads. A NearStore VTL system fully populated with disk shelves can be deployed in seconds, since lengthy disk initialization and formatting procedures are not needed. Resilient, selfdescribing data structures embedded within the JOS eliminate the single points of failure commonly found in the metadata stores of competing VTLs. Metadata imbedded into the JOS makes it possible for RAID groups to be imported into a new controller and eliminates the need for special procedures to guard against controller failure, and write coalescing provides superior reliability and performance.
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Figure 4) NearStore VTL automatic RAID configuration
3.8.1
RAID Rebuild
When a single drive failure occurs, the RAID group in which it resides becomes degraded. VTL OS redirects write activity to other RAID groups, and the degraded RAID group becomes read-only. The rebuild ignores empty space and reconstructs only the data using VTL OS parity. This results in the RAID group coming back online four to 20 times faster than competing VTL systems.
3.9
ADDI TION AL FE ATURES
– – Custom virtual libraries and drives make NearStore VTL very flexible when integrating into legacy environments. Port mapping combined with host masking provides the tools needed to get the best connectivity and performance from NearStore VTL, while maintaining strong security and access control policies in a SAN environment. Role-based access control allows for NearStore VTL to be seamlessly integrated into standard data center operations workflow. Capacity over-allocation allows for minimal resource deployment when testing multiple backup schemas.
– –
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3.10 NETAPP TECHNOLOGY: 100% OWNERSHIP
Competing VTLs from other vendors often contain significant components that have been OEM’d from third-party companies, which limits VTL vendors’ ability to develop their products in line with the requirements expressed by customers and makes it difficult for them to provide enterprise levels of support for the components of the product, which they do not develop themselves. NetApp ownership of the complete VTL solution facilitates complete control of product development, allowing NetApp to evolve the product in close alignment with the needs of customers and provide true enterprise support across all aspects of the NearStore VTL system.
3.11 DECRU® D ATA ENCRYPTION (OPTION AL)
The NearStore VTL can be configured with Decru DataFort® appliances to provide industry-leading encryption of backup tapes at wire-speed performance. Decru DataFort can be used to encrypt data before it is written to the VTL, or it can be used to encrypt only the off-site tapes. The combined Decru and NearStore VTL solution leverages NetApp encryption technology leadership to deliver a comprehensive data protection solution. Lifetime Key Management™ removes the administrative burden of keeping encryption keys securely available for data access and disaster recovery.
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4.1
NEARSTORE VTL: INTEGRATION WITH NETBACKUP
IMPORTANCE OF CRE ATING PHYSIC AL TAPE
NearStore VTL is not typically deployed as a complete replacement for physical tape, but is more commonly used to enhance environments that use physical tape and address problems that are commonly found in the traditional tape space. Its purpose is to provide legacy tape environments with the benefits of random access disk without the disruption that other disk-to-disk data protection solutions can cause. Investments in physical tape and NetBackup agents can be leveraged with NearStore VTL to extend the useful life of tape libraries, tape drives, and tape media, in addition to investments in data protection software licenses. Intellectual investments (training costs) in data protection software and backup and recovery operations are also preserved.
4.2
PHYSIC AL TAPE CRE ATION METHODS
The traditional method of creating physical tape in a NetBackup environment is to use the NetBackup Vault software to copy backup images from virtual tape to physical tape. NearStore VTL supports this functionality and also offers an alternative method of tape creation that offloads the NetBackup media server from the task of duplicating backup images from disk to physical tape. When this option is selected, the NearStore VTL migrates the virtual tape media to physical tape media. We refer to this method as direct tape creation by the VTL appliance.
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Figure 5) Physical tape creation methods conceptual diagram Backup Server Tape Creation Conservative but inefficient
► ► Application tracks all tapes Backup server performs both original backup and backup image duplication – ► ►
Direct Tape Creation Fast, efficient, and compatible
Offloads physical tape creation from media server to VTL 100% compatible with NetBackup media management
4.3
USING NETB ACKUP TO CRE ATE PHYSI C AL TAPE CO PIES
The traditional method of creating physical tape from disk storage units and VTL devices is to use the NetBackup media server to duplicate backup images from the source device (DSU/VTL) to the destination device (physical tape). This method is supported and is an acceptable method for creating physical tapes. The NetBackup Vault extension is typically utilized to manage duplication of images to physical tape in larger enterprise environments.
4.4
USING NE ARSTO RE VTL DI RECT TAPE CRE ATION
NearStore VTL offers the choice of direct tape creation of physical tapes. NearStore VTL’s direct tape creation provides the NetBackup environment with a new way to create physical tapes that has better performance and transparent, policy-based virtual tape retention on disk. NearStore VTL manages direct tape creation with Smart Sizing and shadow tapes. These key features make creating physical tapes from NearStore VTL a powerful feature that is not matched by competing VTL solutions.
4.4.1 NearStore VTL Direct Tape Creation Design Philosophy
A key design philosophy of NearStore VTL is to make the appliance transparent to the backup application (that is, NetBackup). For this reason, tapes created by NearStore VTL are in 100% native format. NetApp ensures that tapes created by NearStore VTL can be read by NetBackup utilizing physical tape drives at a disaster recovery site (even when NearStore VTL is not available). Additionally, there is a one-to-one mapping of virtual tape barcodes to physical tape barcodes so that the user does not have to manage mapping of barcodes or manually track the tapes. When NetBackup requests barcode ABC100 for a restore, ABC100 is the tape that the data protection operator inserts into the physical tape library for restores. The NearStore VTL does not complicate matters by getting in the middle of media management that is already provided by NetBackup.
4.4.2 Smart Sizing in Practice
The Smart Sizing feature of NearStore VTL includes two major technological components. The first component leverages detailed understanding of the various compression methods that physical tape vendors use in tape drives. The second component consists of intelligent software that statistically samples backup streams as they enter the NearStore VTL device. The purpose of Smart Sizing is to ensure that the backup images will fit on physical tape efficiently when duplicating virtual tapes to physical tapes. Smart Sizing does not do anything to the backup image; it simply manages the size of the virtual tapes so that they will fit on physical tapes without wasting space. By monitoring the compressibility of the data, NearStore VTL will send the end of tape (EOT) marker to NetBackup Tape Manager (bptm) when the tape is approaching the
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physical limit for the specific tape device that is configured. Through its understanding of different tape drive compression algorithms, NearStore VTL sizes the virtual tape volume size based on the correct tape drive hardware’s compression algorithm, as well as the sampled compressibility of the data. This ensures good utilization of the physical tape media without the risk of the data not fitting on the physical tape. Competing VTL solutions do not offer this feature and instead force the user to statically size virtual tapes to match the uncompressed capacity of their physical counterparts. Since actual compression ratios are unknown, the native uncompressed capacity of the tape is the only safe choice for a user. This results in a 3 substantial increase in the number of tape media that are required.
Figure 6) Optimized tape utilization with Smart Sizing
Source: VeriTest.
4.4.3 Direct Tape Creation with Shadow Tapes
Shadow tapes are the feature that automates image retention of virtual tapes on disk and manages disk space on NearStore VTL to allow customers to gain the maximum useful benefit from the capacity they have purchased. After virtual tapes are duplicated to physical tape by the VTL and the virtual tapes have been ejected from the virtual tape library using the NetBackup eject command, virtual tapes are moved into the shadow tape pool and are hidden from NetBackup. This is important because it allows NetBackup to correctly track and manage the physical copies. Shadow tapes also manage the retention of virtual tapes on the NearStore VTL appliance. The feature is turned on per virtual library, and images will be retained
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In most cases the number of tapes utilized is doubled. 13
until the appliance reaches 85% of total capacity. At this point images will be cleared to make room for new backups, and an alert will be sent to the administrator. Virtual tapes that reside in the shadow tape pool are available for instant restores if a file restore becomes necessary. Priority for the capacity used by shadow tapes is given to new backups, so if disk space is needed to store new backup data, the older shadow tapes will be removed from the disks of the system to make room for newer backups.
4.4.4 Direct Tape Creation Integration with Vault Reporting
NearStore VTL direct tape creation can be integrated with NetBackup Vault for tracking and reporting of off-site tapes. Vault handles ejecting tapes from the virtual tape library. If the tapes were previously cloned, the physical tapes are immediately 4 sent to the entry exit port (EEP). If tapes were not previously cloned, an export would be initiated, and tapes would be placed in the EEP after the export completes. The workflow is identical to the operations performed if it were Vault duplicating the images.
4.4.5 NetBackup Integration with Shadow Tape: Shadow Tapes API
NetApp and Symantec have committed to providing deeper integration to facilitate more seamless operation between NetBackup and a NearStore VTL. This joint initiative will be available with NetBackup 6.0 MP5 and will allow a NetBackup restore to take place from either a shadow tape or from a physical library connected behind the NearStore VTL without the need for operator intervention.
4.5
DIRECT TAPE CREATIO N/SH ADOW TAPES: BENEFI TS The benefits of direct tape creation with shadow tapes are:
• • • • • • Performance when creating physical tape Reliability Simplified administration Reduced disk real estate for NetBackup catalog Excellent tape utilization with Smart Sizing Elimination of multiplexing for improved disaster recovery time objective (RTO)
4.5.1 Performance Copying to Tape
NearStore VTL direct tape creation offloads physical tape creation from the NetBackup Media Server to NearStore VTL. Essentially direct tape creation performs large-block sequential reads (from VTL) into large-block sequential writes (onto physical tape), which keeps the physical tape streaming for optimal performance.
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The entry exit port functionality is an option that can be configured. 14
Figure 7) Performance benefits of direct tape creation chart
Source: NetApp internal testing.
Notes:
1) This example uses LTO-3 tape drive technology. 2) 25GB was backed up to virtual tape for the comparison: - Vault duplicated images from virtual tape to physical tape. - NearStore VTL direct tape creation duplicated virtual tape to physical tape. - NearStore VTL direct tape creation was 33% faster than Vault in this example.
4.5.2 Reliability
Tape drives that are kept streaming have better longevity because shoe-shining is eliminated. Shoe-shining places unnecessary strain on the tape drive mechanism and the tape media when it has to reverse direction in order to reregister the tape. In addition, RAID-VTL protects the user from data loss. Physical tape drives do not have RAID protection.
4.5.3 Simplified Administration
Shadow tapes automatically manage image retention and disk space so that older images automatically free up disk space according to policy, so that data protection staff does not have to micromanage disk space. When disk space is limited, priority is given to new backups. Tape drives are kept streaming, and their duty cycle is reduced. Less time is spent troubleshooting tape issues as the tape infrastructure becomes more reliable. Instant creation of new libraries as the system grows provides flexibility that cannot be matched by physical tape systems. NearStore performance is automatically managed by self-tuning because backup streams are automatically directed to RAID groups with fewer streams/load. The NearStore VTL GUI simplifies management. Online addition of new disks makes it simple to add more disk storage because data-production administrators do not have to make intellectual investments in storage management skill sets. Additionally,
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the graphical virtual library visual provides better visibility than peering through the window on most physical tape libraries and is familiar and intuitive.
4.5.4
Additional NearStore VTL Benefits for NetBackup
NearStore VTL minimizes/eliminates the need for multiplexing, which can greatly reduce the RTO when compared to tape-only environments where multiplexing is required. The ability to present multiple libraries eliminates the need for tape drive sharing to reduce the complexity and increase the reliability of the backup infrastructure by providing virtually unlimited tape drive resources. When used with NDMP, NearStore VTL can present a virtual library to each NetApp storage system and provide enhanced backup and recovery performance. NearStore VTL can provide multiple data paths to tape drives and supports 5 NetBackup 6.0 tape drive multipathing, which provides active/passive tape drive multipathing. When a path fails, jobs will fail with a status 84 (media write error), but will succeed on a retry using the alternate path.
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CONCLUSION
Network Appliance and Symantec offer products that naturally work well together. Industry-leading NetApp storage and NetBackup integration demonstrate the degree of collaboration and synergy the two companies share. NearStore VTL’s self-tuning, highspeed disk cache dramatically improves the ability to complete backups within the backup window and delivers enhanced reliability by removing mechanical handling of tapes from the backup window. The addition of optimized RAID-VTL protection provides another level of protection previously unavailable to NetBackup users who are using physical tape exclusively. High-speed, hardware-based compression dramatically increases disk-based retention for backup sets, enabling more backup data to be made available for high-speed disk-based restores. NearStore VTL’s optimization of physical tape performance and capacity extends the useful lifespan of existing tape library hardware and media. For more information on NearStore VTL, please contact Network Appliance at (408) 8226000 or visit our Web site at www.netapp.com.
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6.1 6.2
REFERENCES
NETAPP NE ARSTO RE VI RTU AL TAPE LIBR ARY PRODUCT P AG E
www.netapp.com/products/nearstore/nearstore-vtl.html
SYM ANTEC H ARDW ARE COMP ATI BILI TY LISTS FOR NETB ACKUP
http://seer.entsupport.symantec.com/docs/278692.htm http://seer.entsupport.symantec.com/docs/280666.htm
6.3
SYM ANTEC NETB ACKUP PRODUCT P AGE
www.symantec.com/enterprise/products/overview.jsp?pcid=1018&pvid=2_1
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NetBackup 6.0 does not support multipathing for medium changers (robots).
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6.4
VERI TEST NETWORK APPLI ANCE NE ARSTO RE VTL600 AND EMC CL ARIION DL710 PERFORM ANCE COMP ARI SON
www.veritest.com/clients/reports/netapp
6.5 6.6
NEW TAPE DRI VE TECHNOLOGY ARTICLE BY CURTI S PRESTON
www.snia.org/farsighted/archives_2006/aug06_ts_analystscorner
NETAPP ANNOUNCES INDUSTRY'S FIRST INTEGR ATION OF LE ADING B ACKUP APPLIC ATIONS WITH VTL APPLI ANCE
http://www.netapp.com/news/press/news_rel_20060718
© 2007 Network Appliance, Inc. All rights reserved. Specifications subject to change without notice. NetApp, the Network Appliance logo, and NearStore are registered trademarks and Network Appliance is a trademark of Network Appliance, Inc. in the U.S. and other countries. Windows is a registered trademark of Microsoft Corporation. Decru and Decru DataFort are registered trademarks and Lifetime Key Management is a trademark of Decru, a NetApp company. Symantec is a registered trademark and Veritas and NetBackup are trademarks of Symantec Corporation or its affiliates in the U.S. and other countries. UNIX is a registered trademark of The Open Group. All other brands or products are trademarks or registered trademarks of their respective holders and should be treated as such.
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