GUIDELINES FOR SELECTING PURPOSE-BUILT BACKUP APPLIANCES Business and Operational Selection Criteria

Transcription

1 GUIDELINES FOR SELECTING PURPOSE-BUILT BACKUP APPLIANCES Business and Operatinal Selectin Criteria ABSTRACT This white paper explains selectin guidelines fr chsing a backup appliance. It identifies the implicatins f sme f these selectin criteria with respect t business and peratinal impacts. The dcument als helps define deduplicatin and cntrasts the types f deduplicatin technlgies which can affect the verall business value f yur selectin. This whitepaper will als include EMC s apprach with its backup appliance, Data Dmain. <Octber, 2014> EMC WHITE PAPER

2 T learn mre abut hw EMC prducts, services, and slutins can help slve yur business and IT challenges, cntact yur lcal representative r authrized reseller, visit r explre and cmpare prducts in the EMC Stre Cpyright 2014 EMC Crpratin. All Rights Reserved. EMC believes the infrmatin in this publicatin is accurate as f its publicatin date. The infrmatin is subject t change withut ntice. The infrmatin in this publicatin is prvided as is. EMC Crpratin makes n representatins r warranties f any kind with respect t the infrmatin in this publicatin, and specifically disclaims implied warranties f merchantability r fitness fr a particular purpse. Use, cpying, and distributin f any EMC sftware described in this publicatin requires an applicable sftware license. Fr the mst up-t-date listing f EMC prduct names, see EMC Crpratin Trademarks n EMC.cm. VMware is a registered trademarks r trademarks f VMware, Inc. in the United States and/r ther jurisdictins. All ther trademarks used herein are the prperty f their respective wners. Part Number H

3 TABLE OF CONTENTS EXECUTIVE SUMMARY...4 AUDIENCE... 4 BUSINESS CONSIDERATIONS...5 COST SAVINGS:...5 Deduplicatin Algrithms:... 5 Glbal Deduplicatin:... 9 DATA LOSS EXPOSURE:...10 EMC Data Dmain Data Invulnerability Architecture: Other appraches: TRANSFORMING IT:...11 Backup Sftware Transfrmatin Applicatin Integratin And ther Services OPERATIONAL CONSIDERATIONS...14 SOFTWARE PATCHING...14 Backup appliance with integrated backup sftware Nde Style backup appliances Dedicated backup appliance cntrller and disks shelves STORAGE EXPANSION...15 Adding Capacity: Other Backup Appliances Adding Capacity: Data Dmain APPLIANCE UPGRADES...16 Upgrading Systems: ther Backup Appliances Upgrading Systems: Data Dmain DAY TO DAY OPERATIONS...17 Trubleshting Overhead CONCLUSION

4 EXECUTIVE SUMMARY Selecting and standardizing n a backup appliance has many lng term ramificatins fr yur rganizatin. There are many newer entries int the purpse built backup appliance market. We have seen many legacy backup sftware prviders cnverting their technlgy int an appliance; this trend is pushing rganizatins t apply mre diligence in their decisin prcess in selecting a backup appliance. This whitepaper fcuses n cmmn business and peratinal challenges that shuld be assessed, as well as explaining its implicatins t the rganizatin. By understanding these challenges, yu can reduce the risk f chsing the wrng appliance. The first sectin will fcus n selecting an appliance with respect t key business criteria. These reasns can affect the business requirements f yur rganizatin. These fall under cst savings via deduplicatin, reducing data lss expsure, and flexibility in rder t meet the evlving the IT landscape. Backup appliances might be able t slve all r sme f yur business challenges; understanding the inner technlgy will enhance yur selectin criteria. The next sectin will fcus n the peratinal manageability aspects, including sme f the day t day peratinal cncerns f running a backup appliance. The market has varying vendrs wh prvide backup appliances; sme have ver a decade f histry in the market and sme are fairly new with less than 2 mdels released year t date. We will cnsider aspects such as strage expansin, appliance upgrades, sftware patching/upgrading the appliance, and trubleshting caveats. There are cnsiderable peratinal pitfalls that need t be understd up frnt in rder t avid falling int architectural hurdles in the future. As we discuss each tpic, we will als explain hw EMC addresses the challenges utlined and hw it simplifies rganizatinal peratins. AUDIENCE This white paper is intended fr IT business leaders and the peratins team that are respnsible fr data prtectin and data availability. Additinally, this dcument is als geared fr the business decisin makers and stakehlders that have respnsibility in selecting a backup appliance. 4

5 BUSINESS CONSIDERATIONS Business cnsideratins fcus n selecting the right technlgy in a backup appliance that can help yu achieve yur business drivers. This sectin fcuses n higher cst savings, reducing risk expsure, and nt limiting yur rganizatins evlutin f IT. We will discuss each f these sectins and identify what needs t be understd fr selecting yur backup appliance. COST SAVINGS: A large reasn fr evaluating purpse built backup appliances is t achieve better mre peratinal efficiencies and reduce existing csts fr yur rganizatin. Organizatins mve t a backup appliance t eliminate the tape management verhead, tape shipping/strage csts, tape acquisitin csts, and tape destructin expenses. Additinally, there are cnsiderable csts in upgrading legacy tape libraries t newer nes, and re-engineering backup plicies fr multiplexing each time tape drives are added. With rganizatinal data grwing at mre than 2x factr each year, a standard backup retentin plicy can yield 16.2 Terabytes (TB) f backup strage fr 1 TB f data t be backed up (assuming a standard retentin perid and 10% change rate). This type f explsive data grwth has pushed the market t adpt data deduplicatin; any backup appliance yur select must have this technlgy enabled s yur rganizatin can reduce its csts. T select the right appliance, diligence must be placed in understanding the impacts f different deduplicatin algrithms and understand the types f glbal deduplicatin; these factrs can increase yur verall spend by 4x. DEDUPLICATION ALGORITHMS: There are tw types f deduplicatin chunking algrithms that affect yur verall deduplicatin rate which can affect yur savings. This algrithm can significantly increase yur spend in the amunt f backup appliance strage shelves yu have t purchase ver the lifecycle f the appliance. That is t say, if ne appliance yields an 8x reductin and anther prvides a 20x reductin, the cst savings will be expnentially mre with the latter device. The main cnsideratin in a backup appliance s deduplicatin algrithm is t understand whether it des true variable length chunking r applies a fixed blck chunking t simulate variable length algrithms. Fixed Length Chunking Vendrs wh prvide backup sftware as their cre cmpetency typically adpt a fixed length chunking algrithm in their appliances. Fixed length algrithms are easy t implement due t the simplicity f the chunking and requires less cmpute verhead. Fixed length chunking is the prcess f breaking the backup data stream int bit blcks f equal size; a hash is then dne n the fixed blck chunk t determine if the data has been seen befre r nt. If it is fund, it is knwn as a hit, and the data wuld nt have t be stred, and the data wuld thus be deduplicated. Sme prducts apply a standard blck size fr all Figure 1. Fixed Blck chunking in deduplicatin its data while sme prducts apply a different blck size depending n the data type it is ingesting. The blck size des nt change in the specific backup data stream; nce the blck size is determined, it will cntinue using the blck size fr the rest f the stream. Only this fixed blck chunk is being analyzed fr a deduplicatin hit even if a larger/smaller blck wuld have prvided mre hits. This can affect the verall deduplicatin rate and thus the verall cst savings fr yur rganizatin. 5

6 While fixed blck chunking is easy t implement and less resurce intensive, it des have a majr drawback. If a bit is inserted int a data file, and the file is parsed again, every blck after the ffset f the bit insertin will be shifted and has a high chance t be a nn-hit. Figure 2. Fixed Blck Chunking and hw data insertin can shift data t create new blcks The diagram abve depicts a cnceptual view f hw a bit insertin can affect the chunking prcess. Once a bit is inserted int that blck, all yur bits are shifted ff by ne. The blck starting with the data insertin and every subsequent blck will be seen as new data. This can drastically affect the deduplicatin rate and yur rganizatins verall cst savings. Many f these appliances intrduced their appliance with this basic chunking technlgy as their initial prduct launch, and has since attempted t add mre intelligence t try t achieve better deduplicatin rates (See Variatins n Fixed Length Chunking). Variable Length Chunking Figure 3. Variable Length Chunking in Deduplicatin 6

7 Variable length chunking, als knwn as variable length segmentatin is similar t fixed blck chunking. A blck f data is hashed t determine if it was stred befre r nt. The main difference is that the blck size is nt fixed, but varies t find the ptimal chunk size t register a deduplicatin hit. EMC s Data Dmain technlgy is designed t segment the data stream in a variable length between 4 Kilbyte (KB) t 12KB. The data is deduplicated in a similar fashin against this variable blck size n matter what applicatin data type it is seeing (databases, file systems, mail data stres, virtualized machines, etc.). Figure 4. Variable Length Blck Chunking and hw data insertin des nt intrduce new blcks With variable length chunking, if a new bit is inserted in the middle f a file, all the bits after that are shifted ff by ne bit. This affects fixed blck deduplicatin significantly. With variable length deduplicatin, the impacts are minimal since the next blcks can shift t find the cmmn blck again; this achieves higher deduplicatin hits. The diagram belw prvides a cnceptual depictin f an initial scan f the data stream and a subsequent scan f the same data stream with a bit inserted. The secnd scan will nly identify ne unique blck as the subsequent blcks are nt affected. Smaller Blck Sizes: Smaller blck sizes als ptimize the duplicatin rate. Smaller blck sizes achieve greater deduplicatin hits, and mre hits yield greater savings. An example f this is trying t deduplicate this dcument against wrds, such as THE and backup strage versus trying t deduplicate this dcument against sentences, such as The first chunking methdlgy is variable. Obviusly, the latter will prvide mre reductins. Sme fixed blck chunking sizes use chunk sizes as large as 128KB making deduplicatin highly inefficient; hwever, this will utilize less cmpute resurces n the appliance. Cmmn Blck Pl: With EMC s Data Dmain, the efficiencies f this chunking algrithm are further ptimized since all data types are deduplicated against the same blck pl. All datasets cming frm all servers are deduplicated against the same 4KB and 12KB blcks. A VMware backup will dedupe against the blcks frm yur database backups, and against yur mail backups. The same blcks are used. With sme ther backup appliance implementatins, a fixed blck is assigned t data types. A database might be set 7

8 at 128KB blcks, and a file system might be set at 32KB blcks. These datasets will never mix, and thus yu cannt achieve higher deduplicatin rates. Cmpare figure 3 with figure 5 t see a representatin f the pls; a cmmn pl can reduce yur verall strage n the backup appliance. Figure 5. Backup Appliance s variatin n Fixed Blck Chunking Variatins n Fixed Length Chunking: EMC s Data Dmain is designed frm the grund up t perfrm deduplicatin and thus can easily achieve variable length chunking withut any perfrmance implicatins. Rather than using a cmmn database t stre its hashes and chunks, it leverages a deduplicatin file system, engineered t facilitate variable length chunking. Other appliances started with a backup applicatin and then added n deduplicatin technlgy; either thrugh acquisitin f anther prduct r thrugh its wn research and develpment. As such, many appliances use a database t stre its metadata; a chunk hash is basically a database lkup t see if a deduplicatin hit ccurs r nt. While a backend database in these appliances makes the implementatin easier, it als restricts the ability t perfrm variable blck analysis in the same data stream. T keep perfrmance, it relies n using larger blcks while jepardizing deduplicatin rates. T try t achieve better deduplicatin rates, an appliance wuld take its fixed blck chunking and apply sme frm f intelligent analysis n the data type. If the data type is a database, it wuld apply a 128KB hash t it. If the data stream is a VMware data set, it wuld apply a 32KB blck chunking. In this sense, the appliance can claim it uses variable length chunking. In effect, the database keeps 32KB chunks stred in the disk away frm database chunks f 128KB. While this pre-chunk size selectin prcess imprves the speed f the database fr prcessing the data stream, it is less efficient in strage. Even thugh a 32KB chunk f data might already exist in a 64KB chunk, bth chunks are stred n disk. This prcess limits the ability t achieve a higher deduplicatin rate thus reducing the cst savings benefits fr yur rganizatin. While this whitepaper fcuses n hardware appliances, understand as well that sme appliances deply a sftware nly deduplicatin technlgy. The sftware is similar t the abve apprach, where the strage plicies are cnfigurable fr a fixed blck size. That means the custmer is respnsible fr assigning the right data stream type with the right deduplicatin blck. Why nt use a small blck chunking fr everything? String billins f chunk hashes and metadata is nt ptimal fr any database. In fact, many ther appliances have strng statements such as Use a larger blck size fr imprved backup thrughput, and smaller chunks prvide better dedupe ratis but increase system I/O lad. If we break ut the math, a 128KB file is chunked t a 128KB chunk, the hash lkup is ne query in the appliance s database; hwever, if the 128KB file is chunked int sixteen 8KB chunks, it is sixteen queries t the appliance s database. Keeping with large chunks is the nly methd these appliances can sustain the required backup thrughput speed and meet yur rganizatin s backup time bjective, albeit at jepardizing yur cst savings. 8

9 GLOBAL DEDUPLICATION: Many appliances claim the ability t perfrm glbal deduplicatin, yet there are subtle differences t what it actually des. T understand this tpic, we need t differentiate between regular deduplicatin, glbal target deduplicatin and glbal deduplicatin. Regular deduplicatin refers t the ability t deduplicate data against the unique blcks stred in yur backup appliance. Glbal target deduplicatin refers t the ability t direct different data types t the same unique blcks stred in yur backup appliance. Glbal deduplicatin refers t preventing these unique blcks t be stred multiple times frm multiple deduplicatin devices. Sme appliances refer t the ability t direct VMWare, Databases, and ther data types against the unique blcks in yur backup appliance as glbal deduplicatin, when in fact; this is knwn as glbal target deduplicatin. Data Dmain s Glbal Deduplicatin Design: EMC s Data Dmain appliance is able t achieve true regular deduplicatin, glbal target deduplicatin, and glbal deduplicatin. It will dedupe all data types under the same dedupe blck pl f 4KB t 12KB chunks. Additinally, every device the Data Dmain is cnfigured as, such as Virtual Tape Library (VTL), CIFS, NFS, OST Device, BOOST device, will dedupe against each ther. Every disk shelve added t the Data Dmain simply expands the unique blck stre; n blck will be written again t anther active shelf. This glbal deduplicatin will yield the highest deduplicatin rates and thus achieve the highest cst savings. Other Appliance s Deduplicatin Design: A vendr can deply its backup applicatin int an appliance, with a large strage subsystem behind it and claim t achieve glbal deduplicatin. This is a cmmn miscnceptin, as it cannt truly achieve this. It applies different chunking sizes based n the data type that it is backing up. If we assume databases chunk at 128KB and file system wuld chunk at 32KB; then a database wuld never have a hash hit against a unique blck fund in the file system. This appliance wuld achieve regular deduplicatin, but nt glbal target deduplicatin. This limitatin is currently the nly mechanism the appliance can scale perfrmance wise, running bth a deduplicatin database in parallel with the backup sftware. Fr this backup appliance, if we create multiple pls, the data will nt deduplicate against each ther failing t achieve true glbal deduplicatin. Alternative backup appliance architectures include systems that cnsist f a cmbinatin f ndes. The building blck is a nde which is a cmpute technlgy, such as a server, with cnnected strage. This allws custmers t scale mdularly. There are few designs like this that can truly achieve glbal deduplicatin, such as EMC Avamar. Avamar has intercnnects that cmmunicate cmmn blcks between each nde, frming a true grid. Unique blcks are stred nly nce in the whle system thus achieving glbal deduplicatin. Other nde based backup appliances have minimal cmmunicatin between ndes; the same unique blck can be stred n each nde f their system. Services are als limited n a nde by nde basis; services cannt span ther ndes t access data. This als affects the verall savings fr yur rganizatin, where yur strage can be up t 4x mre. Figure 6. Backup Appliance that leverages nde builds 9

10 As we discussed previusly, there are sftware nly appraches fr deduplicatin. These prducts suggest that yu can leverage cmmdity disks. But if we analyze the sftware rllut best practices, they recmmend creating different servers fr different chunk sizes, and t make sure the plicies redirect the right clients t the right pls. There is n glbal deduplicatin r glbal target deduplicatin as there are multiple databases serving each chunking blck size. This can be extremely cstly as yur csts can multiple t as many chunk sizes (server deplyments) yu define. Alternatively, yu can stick with a single chunk size; hwever, yu will get pr deduplicatin rates. As we discussed in the sectin fixed length chunking, this can increase yur strage csts significantly. Ddeduplicatin algrithms and chunking methds need t be understd when selecting yur backup appliance. Understanding the different frms f deduplicatin f these Figure 7. backup appliances allws yu t select the mst efficient device and increase yur verall cst savings t yur rganizatin. Sftware deduplicatin s apprach t fixed blck chunking DATA LOSS EXPOSURE: With Deduplicatin technlgy, extra attentin needs t be placed n the crrectness f the stred unique blck. A unique blck in yur deduplicatin backup appliance affect significant amunts f backup cpies. An analgy we cmmnly use is, deduplicatin is similar t reducing yur favrite nvel dwn t the letters A t Z. If we lse any letter, it can result in yur nvel being unreadable. Yur rganizatin is spending cnsiderable effrts and mney t ensure prtectin f its data. Ensuring yu buy a slutin that can prtect its deduplicatin blcks frm crruptin a firm necessity. EMC DATA DOMAIN DATA INVULNERABILITY ARCHITECTURE: EMC s Data Dmain was designed with the engineering principal f keeping yur data safe. The develpers understd the imprtance f each blck f data in a deduplicatin subsystem. Additinal t standard hardware redundancy, such as RAID-6, Data Dmain als cnsists f a self-describing meta-data file system with self-healing capabilities. When data is written t disk, it is re-read again t verify that n crruptin has ccurred t prtect against ptential disk errrs. These prcesses, including ther data prtectin guidelines, are termed as Data Dmain s Data Invulnerability Architecture. Data Dmain s subsystem is built arund keeping yu backup data safe, as it is the backup n a Data Dmain is the data f last resrt. Mre infrmatin can be fund in the white paper, EMC Data Dmain Data Invulnerability Architecture: Enhancing Data Integrity and Recverability at OTHER APPROACHES: There are 2 areas f prtectin fr backup appliance and/r sftware deduplicatin technlgies: Prtecting the database, and prtecting the deduplicatin blck data stre. Certain vendrs apply ne, bth r nne f these prtectin mechanics. Deduplicatin Chunk Stre Prtectin: The deduplicatin data stre is extremely imprtant and data crruptin can be fatal t any backup recvery hwever, many appliance makers rely n hardware raid t prtect its deduplicatin chunk stre. While RAID prtects the data frm hardware failure, it des nt prevent it frm data crruptin. 10

11 Appliances that supprt replicatin will ask the rganizatin t create a replicatin cpy at anther site; this is t prtect against data crruptin since they d nt have wrking prcesses n prtecting the data easily. A replicatin cpy is an added cst t an rganizatin lking fr a single site slutin, r simply nt requiring tw cpies f their backup data. It is imprtant t understand the mechanics that prtect the data n yur appliances yu are evaluating t ensure yu are buying a recvery slutin that can recver frm data lss itself. Deduplicatin Database Prtectin: The secnd frm f prtectin yu must apply with certain appliance technlgies is t the deduplicatin database. Prper prtectin must be applied t the deduplicatin metadata database as with any prductin database. Many rganizatins classify the deduplicatin database as a tier 1 system because f the imprtance. Sme appliances d nt have any mechanism t prtect their deduplicatin database, while ther appliance appliances have recently adpted scripts t clean the database and verify integrity. These scripts have been created after many iteratins f the deduplicatin technlgy have been intrduced. Sme sftware nly slutins recmmend, and even prceed with scheduling f daily backups f the metadata database. These prtectin mechanisms can be extremely expensive t the cmputer cycles and t strage. Scripts ran t traverse the database can negatively affect the backup appliance s perfrmance; running scripts n the deduplicatin engine can affect the backup applicatin s perfrmance since they run parallel in the same system. Additinally, any deduplicatin database backups can be cstly in peratins verhead and in strage csts. These effrts and csts need t be understd, such as architecting where t stre these subsystem backups, and then multiplying it fr each appliancein the envirnment. T ensure yur backup appliance will be able t recver yur systems when disaster happens; ensure yu understand the prtectin mechanisms f the backup appliance. As well, understand the cst, infrastructure verhead and perfrmance impacts f running these prtectin mechanics. TRANSFORMING IT: A backup appliance can be a fair investment in time and capital; will this appliance meet yur crprate directin r IT evlutin? This sectin identifies if the backup appliance will enable r limit the crprate IT radmap. While the backup appliance will be yur repsitry fr yur backup data, having it serve ther purpses will be a large benefit fr yur rganizatin. By having the same slutin capable f supprting mre use cases, yur rganizatin can save n management verhead, training, deplyment csts and strage (if the appliance des true glbal deduplicatin). BACKUP SOFTWARE TRANSFORMATION Organizatins typically evaluate a backup appliance during sme frm f upgrade t the existing backup envirnment, such as cde upgrade, server upgrade, tape library upgrade, r changing the backup sftware prvider. Many f these events can have cnsiderable temprary architectural csts. Fr rllut f new servers r new backup sftware prviders, there might be situatins that require yu t duble yur backup infrastructure. There is a strng requirement t have the data available fr recvery at any time as yu upgrade yur systems. The ld data must be available fr recvery until the new system has retained enugh gd cpies t meet yur recvery bjectives. Typically, bth the ld and the new systems and assciated backend strage need t be up and running in parallel. There is als a heavy dependency n rllut timelines since yu typically can t d a single day cnversin f all yur rganizatins clients frm ld t new. Even when clients are cutver, yu must retain the lder envirnment until the new system has enugh backups t meet yur cmpliance needs. Figure 8. Duble the strage during intrductin f new backup server 11

12 C mpanies require a methd t leverage the existing backup strage infrastructure intact fr recvery and cmpliance, as well as a new backup strage infrastructure t start new backups. Traditinally, this means allcating even mre strage fr the new backup infrastructure and wait frm weeks t years befre the ld strage can be reused. (See Figure 8) Having a single backup appliance that can supprt bth the ld envirnment as well as the new envirnment cncurrently slves the abve prblem. Fr example, have yur ld systems send the data t the backup appliance; then deply the new servers t send their backup data t the same backup appliance. This eliminates having duble the data written t tw strage devices during yur migratin. If the appliance supprts glbal deduplicatin, the blcks frm the ld and the new envirnment will dedupe against each ther; this further reduces the cst fr yur rganizatin. (Figure 9) When selecting a purpse built applicatin, understand if yur appliance is lcked in with the backup sftware. Als, understand if the deduplicated strage can be used t facilitate upgrades as we discussed. Are yu tied in with the deduplicatin strage since it nly wrks with the appliance s technlgy r is it penly useable fr ther backup sftware? Many appliances have the strage tied with the backup sftware limiting yur ability t leverage the strage cmpnent. EMC s Data Dmain slves the abve challenges. Data Dmain allws multi-use Figure 9. Data Dmain can cnslidate strage during upgrades functinality, s multiple services can be represented t the same backup appliance. Additinally, different backup sftware at can be presented t the Data Dmain at the same time. This multi-use functin can facilitate upgrades f sftware, servers, r ther infrastructure cmpnents. The Data Dmain s glbal deduplicatin technlgy allws mre efficient cutver and can yield higher csts savings. Data written frm ne backups sftware will dedupe against data frm anther backup sftware (whether they are the same prduct, different versins f the same prduct, r cmpletely different sftware). Having a backup appliance that can facilitate multiple use scenaris and at the same time prvide glbal deduplicatin can benefit yur rganizatin. This hlds especially true if there are plans fr sme frm f backup transfrmatin. APPLICATION INTEGRATION AND OTHER SERVICES Anther key cnsideratin f selecting a backup appliance is t understand yur rganizatin directin with virtualizatin, such as VMWare, Micrsft applicatin backup, Oracle backup, and ther lng term cmpliance requirement, such as archiving. By having a single backup appliance that can be a single repsitry fr each f these applicatins can further reduce yur rganizatins cst. The prper backup appliance can be an enabler fr these ther technlgies. Cmmn Integratin pints with Backup Appliances: Depending n the appliance, the additinal integratin pints vary greatly. Certain backup appliance allws leveraging the strage fr multiple ther technlgies and/r functins, ther than a target fr backup. Vendrs that design their architecture by tying in the backup sftware with the cmpute layer and strage layer in a single appliance might be limited in what the disks can be used fr. In many cases, the internal strage f these appliances is limited fr the backup applicatin t use and nthing else. This further reduces the benefits f a mass pl f deduplicated blcks that can benefit ther applicatins. Other appliances have added functinality int its cmpute layer ndes t ffer CIFS, NFS and VTL functinality. Hwever, these technlgies usually limit the data t the nde s disks, and nt t the whle system. In ther wrds, nly a subsectin f the disks f the system can be used fr the extra services. In sme appliances, the service will have an islated deduplicatin pl and wuld nt able t prvide the benefits f glbal deduplicatin in the same appliance. Since services are applied nly t the ndes, there will be limits t yur rganizatin, bth in cst savings and scalability. 12

13 EMC Data Dmain Integratin Pints: EMC s Data Dmain prvides multi-functin access. It can be a backup repsitry stre fr yur tier 1 backup applicatins, such as EMC, Symantec, HP, IBM, VDPA, CmmVault and thers. It can leverage a single Data Dmain t create multiple target devices including a cmbinatin f Virtual Tape Library, CIFS, NFS, and BOOST/OST. The Data Dmain appliance can ffer ther use cases t extend its capabilities fr yur rganizatin. Its BOOST library is extended t supprt direct applicatin integrated backups. The Data Dmain can be made accessible t yur ther peratins teams, including VMware administratrs, SQL Server administratrs, and Oracle Administratrs. Sme f the examples include: VMware integratin fr VM Archiving VMware Data Prtectin Advanced (VDPA) integratin fr VM backup and recvery, SQL Server management studi plug-ins fr SQL DBA direct bakup, BOOST libraries fr Oracle RMAN fr Oracle administratr RMAN integrated backups, and many ther integratin pints. These functins further enhancing the use cases fr the Data Dmain, and lwering yur cst since it achieves true glbal deduplicatin acrss all f these repsitry stres. One f the cmmn expanded uses fr the Data Dmain is t enable RMAN backups fr Oracle administratrs. While the Data Dmain is deplyed as the strage repsitry fr the enterprise backup sftware, a custmer wuld enable RMAN BOOST access t the same Data Dmain. This is enabled via a BOOST library that RMAN takes advantage f directly; yur DBA s can get the cntrl they require. By enabling bth device access pints, the Data Dmain can help the rganizatin achieve further cst savings by glbally applying deduplicatin n the racle dumps against the chunks frm the backup applicatin. Oracle administratrs run the same native tls, while the rganizatin saves n Tier 1 SAN space, where the DBA s wuld dump the Oracle databases. Having advanced applicatin integratin is necessary t achieve the best utilizatin f a single prduct; this ability f an appliance can reduce peratinal verhead f deplying multiple pieces f technlgy. Other than being accessed by yur backup applicatin, what ther features and functins des the backup appliance have? Will data deduplicate glbally acrss all the ther disks in the shelves and ndes fr further savings? Can yu leverage thse deduplicated blcks fr ther purpses? Data Dmain has an extensive list f ver 20 Enterprise grade archiving and cntent management applicatins, direct applicatin integratin with SAP, Oracle, SQL server, etc. and supprts every Tier-1 enterprise backup applicatin n the market. 13

14 OPERATIONAL CONSIDERATIONS There can be many caveats frm the peratins f a backup appliance that rganizatins might nt be aware f until they have actual experience running them. This sectin explains what needs t be understd peratinally upfrnt since it has ramificatins fr yur rganizatin in the future. Each sectin fcuses n different aspects f perating and architecting a backup appliance and what needs t be identified befre selecting a prper backup appliance. SOFTWARE PATCHING Backup appliances need t be patched and upgraded t fix bugs, and btain new features, similar t patching yur perating system. This sectin discusses any caveats that need t be understd arising frm peratinal patching yur backup appliance. It lks at the different architectures and highlights areas fr cncern. BACKUP APPLIANCE WITH INTEGRATED BACKUP SOFTWARE Many appliances created by traditinal backup sftware vendrs have added deduplicatin by leveraging a metadata database. The deduplicatin backend further evlves their prduct ffering. Initially, the backup appliances were simply media severs in a vendr specific server; recently, these vendrs have added strage t prvide a single device that cntains the backup applicatin layer, cmpute layer and strage layer. Mst rganizatins that adpt these backup appliances are thse that have a lng standing histry f running the backup applicatin. Hwever, the team shuld als understand previus upgrades f the backup sftware and what it entails. With the intrductin f the metadata database within the backup applicatin, the risk f the patch can affect mre systems. A patch is nt just a backup applicatin patch anymre, but the patch can affect the database and the hardware peratins. Will the patch f the backup applicatin layer put the database r data at risk? Will I require mre patches and upgrades since nw there are three elements (hardware, backup sftware and database)? Hw can these patches be prperly tested befre peratinalized? NODE STYLE BACKUP APPLIANCES Sme vendrs have develped a backup appliance system with a multi-nde architecture. By having a system created with multiple redundant ndes, they can maintain high thrughput but can add mre cmplexity in patching the system. C ertain appliances rely n patching each f the redundant ndes in the entire system. If the system supprts 4 redundant ndes, an rganizatin may require 8 r mre maintenance jbs. Additinally, each nde upgrade affects specific services in that nde. The peratins team wuld have t verify and test each service after the nde upgrade. The patch wuld have the same caveats as the previus functin, since each nde wuld have its wn deduplicatin database and cmpute layer. There are ther backup appliances that perate in a grid, such as EMC s Avamar, where the patch is prpelled thrugh all the ndes. This simplifies upgrades since there are less pints f interactin. With Avamar, yur data is prtected as internal snapshts are created t rll-back the system in the event f issues. The Avamar upgrade practices minimize the rganizatin s risk and expsure t data lss. DEDICATED BACKUP APPLIANCE CONTROLLER AND DISKS SHELVES EMC s Data Dmain has a self-describing data frmat built in which enables faster perfrmance; the data structure allws deduplicated data t be systematically rebuilt frm the metadata. This frmat frms the Data Dmain deduplicatin file system. While the cntrller runs the services fr the backup applicatin t access, the deduplicated data is frmed via accessing the disk shelves. The Data Dmain cntrller simply munts the deduplicated file system. Any upgrades and patches f the cntrller system d nt affect the deduplicated data, ensuring data recverability. Even if a patch were t destry the cntrller, yur data wuld be safe. Mre infrmatin can be fund in the white paper, EMC Data Dmain Data Invulnerability Architecture: Enhancing Data Integrity and Recverability at 14

15 STORAGE EXPANSION Strage expansin discusses the additin f strage t yur backup appliance. When yur appliance is running ut f space, it is time t begin the prcurement and architectural prcess t purchase and add capacity. Understanding hw capacity is added t each f these systems can avid headaches later n. ADDING CAPACITY: OTHER BACKUP APPLIANCES The majrity f the backup appliance appliances supprt basic strage expansin. Capacity can be added with the prcurement f the disk shelves and assciated licensing f the capacity. Once the strage is added, the system can be restarted with the expanded space. Sme appliances require a pst prcess f recgnizing the strage and adding it t the strage pls fr utilizatin, usually dne thrugh wizards. Reaching Capacity: The main peratinal cncern is when yur backup appliance is reaching its maximum shelf capacity. Sme appliances might be restricted at having a maximum f 2 shelves f disks while sme can scale t having many mre shelves. Prblems arise when new systems are being brught up in yur rganizatin that require backup and yur appliance is reaching maximum capacity. Knwing that yur backup appliance can nly increase an extra shelf, yu are stuck at a typical junctin pint. The current existing machines in the envirnment need t cntinue backing up, and sme f them have lng retentin perids. That is t say, the existing clients might have retentin perids f mnthlies and yearly cpies defined n it which will cnsume extra space even with deduplicatin applied. On the ther hand, yu have new systems that are being deplyed that will need backup capacity. D yu cntinue with adding the new machines t the appliance? Or d yu start prcuring a new backup appliance t backup thse new systems as well as disks t grw the existing appliance? This wn t be very efficient fr deduplicatin, because the new appliance will have its wn pl f unique blcks which might repeat acrss the ther appliance. While yu may be assuming this is an easy prblem t fix, it actually has a lt f space implicatins. The new clients will generate unique blcks under the deduplicatin prcess. Even if the majrity f the blcks are cmmn, there will be blcks frm these new clients that are unique. (Figure 10) These blcks will cntinue t grw as the new clients are hitting its retained Figure 10. Unique blcks created by intrducing new clients t deduplicatin pl cpies f weeklies, mnthlies and yearly cpies. Similarly, the existing clients are grwing fr the same reasn. There will be a time when yu will need t migrate thse clients t a new appliance. Depending n the backup appliance, there might nt be a simple migratin prcess t mve the unique blcks relevant t the new clients frm the ld appliance t the new appliance, meaning they are stuck there. Yu might be able t make create plicies t cpy f the data and replicate it acrss, but there might nt be a way t eliminate thse blcks frm the ld backup appliance (r even cleanse it frm the metadata database). Nw, yur ld appliance might be in a state with sme f the new client s blcks n it, the backup appliance is at capacity, and yur existing clients are running ut f space t achieve its retentin cpies. These prcesses need t be understd befre yu begin sizing yur backup appliance. Migrating Plicies: There are certain architectural cnsideratins that need t be understd with the prcess f migrating clients t free up space especially n systems that tie in the backup applicatin and the strage. If the appliance is tied with the backup applicatin, the newly purchased appliance might be cmpletely islated in which case a migratin is nt pssible. Backup plicies might need t be recreated and the clients reinitialized t the new system. 15

16 Alternatively, if the new system is running as a media server cntrlled by the legacy appliance then sme frm f migratin might be pssible. Since the backup applicatin is running n the appliance, it will maintain the catalg, the plicies and all awareness f the data. The backup plicies will have t be redirected frm this backup appliance t the ther backup appliance. After the plicies are migrated, yu will need t clne the backup jbs. Depending n the amunt f time the clients were running n the legacy appliance, this can be hundreds f backup jbs t clne. Alternatively, yu can retain the ld jbs n the legacy appliance and create new jbs n the new appliance. During restre, yu will have t grant appliance wnership f the restre jb t crrect appliance in rder fr the jbs nt t fail. Yu will als need t keep bth appliances running until the legacy data expires. Anther frm f backup appliances is systems that cmprises f ndes. Each f thse smaller ndes run independent deduplicatin stres and is themselves limited t the number f shelves. The same prblem arises as discussed abve. What happens when yu reach capacity? The prblem is actually cmpunded as there is n glbal deduplicatin happening in many f these appliances. The ndes dn t inter-cmmunicate unique blcks between each ther in the system. If ne nde is full, yu will need t redirect the clients t ther ndes in the system. Yu will als need t create the respective services n that new nde with capacity; this will effectively duble the space cnsumed. There will be cnstant manual rebalancing nce yu start reaching capacity thrughut the ndes. This state will start dubling the unique blcks each time clients are mved acrss ndes in the system. Additinally, a lt f these appliances state directly that as the metadata database grws, the perfrmance f the backup appliance will begin t diminish. The alternative t this design is EMC s Avamar. EMC s Avamar functins as a true grid, where ndes frm a single entity; inter-cmmunicatin cntrls which nde hlds which unique blck t maximize deduplicatin ratis. ADDING CAPACITY: DATA DOMAIN EMC s Data Dmain prvides shelf additins t expand capacity. The capacity is shared with every service yu enable and is glbally deduplicated acrss all its devices it creates. If yur Data Dmain reaches the maximum number f shelves supprted, a simple cntrller upgrade can be perfrmed. This will increase yur thrughput and the maximum shelves yu can grw t. Yu backup sftware will perate independently frm the Data Dmain; there will be minimal t n wrk required n capacity upgrades f the Data Dmain backup applicatin. The Data Dmain des nt run a metadata database fr hash lkups s strage additin des nt negatively affect perfrmance. The remval f expired data is autmated and dne in a data secure methdlgy fllwing the Data Invulnerability Architecture. APPLIANCE UPGRADES Appliance upgrades discusses hw t upgrade yur backup appliance when it reaches capacity r the hardware becmes end f life. It explains the caveats that can arise when upgrading yur backup appliance. A deduplicatin enabled backup appliance can cntain hundreds f terabytes f data t petabytes f data. Understanding system upgrades can help identify ptential impacts t yur rganizatin, pssible dwntime expsure, and the wrklad required t perfrm such upgrades. UPGRADING SYSTEMS: OTHER BACKUP APPLIANCES Many vendrs nly have a limited amunt f appliance mdels and d nt supprt upgrades histrically. In sme instances the vendr wuld ask the rganizatin t wait fr the retentin t expire befre shutting dwn the legacy appliance. Other times, they wuld ask the custmer t replicate the hundreds f terabytes f data t the new appliance and recreate the plicies, and migrate the catalg. This prvides lengthy upgrades, increases risks t the rganizatin, and affects yur day t day backup/restre rutine (r even stps it). During this replicatin prcess, the metadata database will be heavily taxed n bth the ld and new appliance since every deduplicated blck will be lked up, pssibly many times ver and ver. This makes any new backups r restres extremely slw. It is imprtant t understand the dwntime and duratin f such upgrades. Organizatins cannt have the backup appliance dwn by days waiting fr a cutver. Additinally, since the prduct line frm these vendrs is fairly new, they might nt have develped an upgrade prcesses t address r understand these issues. 16

17 Sme appliances allw yu t add ndes in the system, but nce yu reach their maximum number f ndes the grwth stps. These prducts typically d nt have an upgrade prcess as well. The system is even mre cmplex t upgrade, as the system cntains several ndes running their wn strage pls and services. EMC s Avamar can supprt grid t grid upgrades via internal cntrlled replicatin; dwntime is minimized as backups cntinue n the new grid within hurs. Avamar is n its 4 th generatin device, with years f experience perfrming grid upgrades. As well, EMC Avamar can leverage the Data Dmain as the backend strage t cntinue t expand strage grwth. UPGRADING SYSTEMS: DATA DOMAIN As we discussed in the previus sectin, cntrller upgrades are perfrmed with EMC services in the duratin f a few hurs. The previus cntrller is remved and the new cntrller is racked. The disk shelves are then hked up t the new mdel f Data Dmain. After a quick cnfiguratin f IP, hstnames, and the generic system requirements, the Data Dmain is ready t again cntinue backing up yur data r restring previusly stred data; the hundreds f terabytes f data is gd t g after this prcess. EMC s Data Dmain strage shelves fllw a self-describing data frmat which enables a simple file system munt f the deduplicatin file system t have the data active and ready t g. Additinally, EMC prvides many mdels frm small remte ffice appliances t large enterprise appliances; EMC allws flexibility in chsing yur mdel t fit yur budget and never limiting yur ability t grw. Sme appliances that cmprise f ndes nly reach 25% f actual thrughput when the system is deplyed as a single nde. Sme f the smaller Data Dmain mdels have data stred n data disks resident in the cntrller. These data drives will be replicated ver t enterprise mdels f the Data Dmain; since the vlume is very small the replicatin f the several drives will be dne quickly. Data Dmain s upgrade prcesses have been designed t reduce maintenance hurs and have been fine-tuned thrughut the years; Data Dmain has a histry f ver a decade in the industry. DAY TO DAY OPERATIONS The last sectin f this whitepaper addresses day t day peratins f backup appliances. Certain appliances perate in a set it and frget it manner, while thers require day t day management. We will discuss the trubleshting caveats and verhead that the appliance places t the administratr. TROUBLESHOOTING Backup appliances that integrate cmpute, strage, and backup sftware will require mre extensive tls t differentiate perfrmance issues cming frm the backup applicatin versus the deduplicatin metadata database. Since the prduct is tied tgether, it is difficult t identify cause/effect. A backup administratr s ability t identify bttlenecks f slw backups will be extremely limited. The cmplexity f the backup applicatin and its inner fine-tuning aspects must nw cexist with the finetuning f the deduplicatin engine. Backup admins wuld have t identify if the bttleneck is cming frm the backup applicatin, the chunking size, the metadata database being t busy, netwrk delays, etc. Als, during trubleshting, perfrming peratinal functins such as shutting dwn prcesses t enable lgs and flags can have adverse effects n the every ther cmpnent in the backup appliance. Since every piece f the technlgy is tied tgether, the administratr might be limited in perfrming any fixes withut taking the whle appliance ffline. Data Dmain is islated frm the backup applicatin. It has its wn perfrmance metrics t identify where bttlenecks are cming frm. The backup applicatin can be perated n r the Data Dmain can be perated n in islatin. OVERHEAD Mst deduplicatin appliances require garbage cllectin and clean up prcesses. As discussed previusly, new scripts have been created in sme appliances t attempt t d crruptin repairs. Understand the scripts impacts t yur backup, recvery and day t day peratins needs t be understd. Data Dmain prducts allw C PU t be thrttled, s perfrmance will be available fr restre and backup prcesses. There will never be a gd time fr cleaning as rganizatins perate 24x7; having cntrl f the cleaning prcess and being able t put threshlds n it can safeguard against backup/restre perfrmance issues. 17

18 CONCLUSION As we identified thrughut this dcument, there are many factrs that play in the selectin f a purpse built backup appliance. As yu lk at yur rganizatin s requirement n the business, the fllwing must be cnsidered in understanding yur backup appliance: Cst Savings: Is the best deduplicatin algrithms being used? Hw des the vendr define glbal deduplicatin? Data Lss Expsure: What is my risk expsure fr the data? Hw will the deduplicated data be prtected? Meet yur rganizatins Evlutin f IT: Is yur rganizatin mving heavily n VMware? Are the Oracle and SQL administratrs asking t expand their tlset? Will yu be mving twards SAP HANA? Will there be new backup sftware r sme IT refresh abut t happen? Will my backup appliance meet my current and future requirements? When we evaluate the backup appliance, cnsiderable effrt will need t be dne t understand the peratinal aspects. Each backup appliance differs in appraches based n their design. The fllwing peratinal caveats must als be understd in selecting yur backup appliance: Sftware Patching: Hw easy will it be t patch these appliances? Will I require mre patching since there are many mre integrated pieces in the backup appliance? Will my data be put at risk with a patch? Strage Expansin: Strage add is easy, but what happens when I reach the scalability limits? Hw d I mve clients frm ne appliance t anther? What happens when the bx is end f life and cntains my data, clients, and catalg? Appliance Upgrade: What happens when my appliance needs t be replaced? Hw d I get the hundreds f terabytes ff it t the new appliance? Can I mve the catalg and assciated backup applicatin mechanics, such as client registratins and plicies t the new appliance easily? Day t Day Operatins: Wuld it be easy t identify bttlenecks with many cmpnents running altgether? Will it be easy t trublesht? What kind f impacts d the cleaning cycles have n the system and my ability t backup/restre? Can I thrttle these activities r schedule them? Gartner s recent magic quadrant released in July 2014 puts EMC s Data Dmain as the tp right leader in deduplicatin backup appliance market, putting cnsiderable distance t ther vendr s technlgies. EMC has clearly addressed these challenges, winning the market share in the purpse built backup appliance market. With ver a decade f experience, Data Dmain has set the bar n feature requirements that all backup appliances shuld minimally have. 18