Dell Compellent Storage Center (SC8000) & VMware View 5. 1,000 Desktop Reference Architecture. Dell Compellent Technical Solutions

Transcription

1 Dell Cmpellent Strage Center (SC8000) & VMware View 5 1,000 Desktp Reference Architecture Dell Cmpellent Technical Slutins

2 THIS REFERANCE ARCHITECTURE IS FOR INFORMATIONAL PURPOSES ONLY, AND MAY CONTAIN TYPOGRAPHICAL ERRORS AND TECHNICAL INACCURACIES. THE CONTENT IS PROVIDED AS IS, WITHOUT EXPRESS OR IMPLIED WARRANTIES OF ANY KIND Dell Inc. All rights reserved. Reprductin f this material in any manner whatsever withut the express written permissin f Dell Inc. is strictly frbidden. Fr mre infrmatin, cntact Dell. Dell, the DELL lg, and the DELL badge and Cmpellent are trademarks f Dell Inc. VMware, ESXi and View 5 are trademarks f VMware Inc. Micrsft are trademarks f Micrsft Crp. Other trademarks and trade names may be used in this dcument t refer t either the entities claiming the marks and names r their prducts. Dell Inc. disclaims any prprietary interest in trademarks and trade names ther than its wn. June

3 Cntents Intrductin... 5 Executive summary... 5 Key findings... 6 Dell Cmpellent Fast Track... 8 Lad Generatin... 8 Virtual Machine Prperties...9 VMware ESXi Windws Antivirus Strage Center Cnfiguratin Data Prgressin, Replay Technlgy Testing Results Bt test Lad Test View Planner Scring Methdlgy VMware View Planner 2.1 Wrklad Results Functinal IOPS Cnclusin Reference Materials

4 Figures Figure 1. Tested Architecture... 8 Figure 2. Virtual Disk Relatinship per Vlume Figure 3. VMware ESXi 5 Datastre Layut Figure 4. VDI-SteadyState Strage Prfile Figure 5. Replay creatin Figure 6. Replay statistics pst wrklad run Figure 7. Ttal IOPS during bt strm Figure 8. SSD IOPS during bt strm Figure 9. 10K IOPS during Bt Strm Figure 10. IOPS with medium wrklad

5 Intrductin The intentin f this dcument is t prvide technical prfessinals with infrmatin t assist in the planning, design and deplyment f a Dell Cmpellent Strage Center SAN in a VMware View 5 VDI envirnment using VMware ESXi 5 as the hypervisr. This dcument is based n internal testing f 1,000 virtual desktps n 16 Dell M710 HD physical blade servers. The data fr this dcument was gathered and validated at the Dell Cmpellent lab and design center. This dcument fcuses n the impact f a virtual desktp infrastructure (VDI) n the Dell Cmpellent Strage Center SAN. As such, detailed infrmatin n hst, netwrk and ther supprting infrastructure is ut f the scpe f this dcument. Hst, netwrk and supprting infrastructure is imprtant t a VDI deplyment and shuld als be carefully evaluated when planning a VDI prject. The infrmatin in this dcument is t serve as a reference t implementing VDI with the Dell Cmpellent Strage Center SAN. Wrklads will be different fr each rganizatin, depending n applicatins and infrastructure. As such, it is strngly recmmended that each rganizatin run a VDI pilt t gather sizing and IOPS data as a basis fr purchasing and prvisining the crrect amunt f strage. Executive summary Prper strage cnfiguratin is imprtant t the success f a VDI prject. Dell Fluid Data architecture and Dell Cmpellent integrated sftware features, such as autmated tiered strage, thin prvisining, cntinuus snapshts and remte replicatin, prvide a highly effective strage ptin fr VMware View. Dell Cmpellent Dynamic Capacity sftware separates strage allcatin frm utilizatin. While administratrs can create strage vlumes f any size fr virtualized applicatins, physical capacity is cnsumed nly when data is written t the disk. With thin prvisining, IT grups can avid purchasing excess capacity upfrnt. When applicatins require mre strage, the system prvisins it frm the pl f unused capacity. Fr instance, thin prvisining can present 10 virtual strage vlumes, 10TB each, fr use by 16 unique servers, but nly require the physical capacity that is actually written fr each hst. In additin, autmated tiered strage frm Dell Cmpellent, called Data Prgressin, can help rganizatins ptimize the use f strage in a VMware View envirnment with VMware ESXi 5. Data Prgressin can statically r dynamically mve blcks f data between tiers f strage based n perfrmance characteristics. This allws the intelligent use f all tiers f strage, withut the write penalty typically assciated with traditinal strage arrays. Utilizing Data Prgressin, all writes int the strage array ccur at Tier 1, RAID 10. Over time, the sftware dynamically mves thse blcks t mre efficient RAID levels, and the less frequently accessed blcks t lwer tiers f strage. Data Prgressin reduces the need fr large numbers f high-perfrmance, high-cst disks by mving frequently used data t higher perfrmance tiers f strage while mving infrequently used data t lwer cst, higher-density disks. The migratin f data is dne n the blck level, s data within a vlume can be mved based n perfrmance characteristics. These technlgies help t create an efficient strage platfrm fr VMware View 5 with VMware ESXi 5. 5

6 Key findings The Dell Cmpellent Technical Slutins team tested a sample f 1,000 virtual desktps and simulated real-wrld wrklads using VMware View Planner 2.1 with VMware ESXi 5 and VMware View 5. The envirnment included a Dell Cmpellent Strage Center SAN, Dell M1000e Blade enclsure, (8) M710HD blade servers, 8Gb Fiber Channel cnnectivity. VMware View Planner 2.1 uses standard ffice applicatins with peridic wait times t generate the simulated wrklad f a typical knwledge wrker. During the deplyment f VMware View 5 virtual desktps, a selectin f what datastre the replica disks, delta disks, and persistent data disks reside becmes imperative t a successful VDI implementatin. Selecting different datastres fr different types f VMware View disks allw a rich end-user experience. Utilizing a Dell Cmpellent Strage Center SAN and 3 SSD drives t create a vlume that stres the VMware View replica disks images helps fflad the heavy read IOPS f a bt and lgin strm. Offlading the heavy read IOPS t the SSD disks allws the higher capacity, lwer IOPS 10k drives t handle the VMware View delta and persistent data disks. Using VMware View Planner 2.1 and the full user wrklad, a peak f 25,000+ ttal IOPS and 400+ MBPS thrughput was bserved during View Planner bt-up initiatin. Read/write percentage during bt-up sequence was 90% read and 10% write. After all 1,000 VDI desktps were bted and the wrklad cmmenced with a steady state f apprximately 5,000 IOPS bserved. The read/write percentage during the steady state wrklad testing was 10% read, and 90% write. In additin t the lad test, a bt strm was emulated by pwering n 1,000 virtual desktps simultaneusly via VMware vcenter. This generated IOPS as high as 36,000. During the bt strm an average f 70% f IOPS came frm the SSD tier f strage, while the remaining 30% came frm the 10K disk tier. While measuring sustained high IOPS, the length f the 1,000 virtual desktp bt strm was apprximately six minutes. Tested architecture The tested envirnment was cmprised f 8 VMware ESXi servers running in ne cluster. The cluster was assigned bth VMware View 5 Desktp Pls. Each VMware View desktp pl cnsisted f 500 VDI desktps. Eleven vlumes were prvisined frm the Dell Cmpellent Strage Center fr each pl and crrespnding VMware VMFS datastres were created n thse vlumes: Five VMware datastres stred the delta disks, five VMware datastres stred the persistent disks and ne VMware datastre stred the replica disks. PwerShell scripts were utilized t efficiently and accurately prvisin each vlume in the Dell Cmpellent array, and present and create the VMware VMFS datastres. (See appendix fr example CSV answer file) Each vlume was 10TB in size; the disk size f 10TB was beynd the requirement fr the test. Hwever, with thin prvisining frm the Dell Cmpellent Strage Center, n space was wasted n the SAN. Additinal infrastructure virtual machines were used t supprt the tested envirnment. This included VMs fr infrastructure tasks, such as Active Directry, SQL Server, Dell Cmpellent Enterprise Manager, VMware vcenter, VMware View 5, and VMware View Planner

7 Test infrastructure Dell M1000e Blade Chassis (2) - Dell PwerCnnect M Fabric A (2) - Brcade M Fabric B (8) Dell M710HD blade servers as virtual hsts fr VDI desktps Dual Six Cre Intel Xen X GHz prcessr 96GB 1333MHz DDR3 SDRAM Quad-Prt Bradcm 1-GbE Mezzanine Card (LAN) - Fabric A Dual-Prt Qlgic Gb Mezzanine Card (Fiber Channel) - Fabric B VMware ESXi 5 sftware (2) Dell PwerEdge R610 virtual hsts fr infrastructure servers Dual Quad Cre Intel Xen X GHz prcessr 72GB RAM Dual-prt Intel 10GbE NIC, Mdel x520-da2 fr netwrk and iscsi Virtualized infrastructure including: 2, AD Dmain cntrllers 1, VMware vcenter 5 server 1, VMware View 5 server 1, VMware View Planner 2.1 Virtual Appliance 1, Dell Cmpellent Enterprise Manager Data Cllectr server 1, Windws Server 2008 R2 file server 1, SQL Server 2008R2 server (2) Dell Cmpellent Strage Center SC8000 cntrllers 16GB RAM 48, 2.5-inch 900GB 10K SAS drives 3, 2.5-inch 200GB SSD SAS drives Firmware Versin GB Fiber Channel Dell Cmpellent Fast Track-enabled 7

8 Figure 1. Tested architecture Dell Cmpellent Fast Track The desktp deplyment utilized the Dell Cmpellent Strage Center SAN feature Fast Track, which dynamically places the mst frequently used data n the fastest, r uter, tracks f each drive. By cntinually ptimizing data placement n each disk, Fast Track eliminates wasted space n the fastest prtin f the drive. In this test, Fast Track was used n every drive within the system. 8

9 Lad generatin T accurately represent a real-wrld scenari, a lad generatin utility was used thrughut the test. The lad was generated using VMware View Planner 2.1 applicatin. VMware View planner replicated a wrklad f 1,000 virtual desktps lgging in and used a variety f ffice applicatins such as Micrsft Office, Internet Explrer, Mzilla Firefx, archiving sftware, and vide playback. VMware View Planner 2.1 initialized a wrklad run that cnsisted f 8 ttal wrklad iteratins. T pass this test, the 95th percentile f applicatin latency must be belw 1.5 secnds. Virtual machine prperties Fllwing VMware View Planner 2.1 guidelines a generic "Base VM" was utilized t create all 1,000 VMware View Cmpser Linked Clne desktps. The template cnsisted f VMware Hardware v.8, 1 CPU, 768MB f RAM, LSI Lgic SAS Cntrller, 1 40GB Eager-Zered Hard Disk, 1GB Eager-Zered Hard Disk, CD-ROM Device and Netwrk adapter (VMXNET 3). Micrsft Windws 7 32-bit was installed as the desktp Operating System. VMware ESXi 5 VMware ESXi 5 Enterprise editin was utilized as the hypervisr fr the guest virtual machines. ESXi strage cnnectivity was cnfigured utilizing the VMware ESXi sftware ISCSI initiatr and the dual prt Intel 10Gb mezzanine cards in each Dell M710 blade server. (Figure.1) vswitch1 was assigned bth Intel 10Gb prts. An ISCSI-1 prt grup and ISCSI-2 prt grup fr each Intel 10Gb prt was a created. Each prt grup had a dedicated physical NIC, IP address and VMkernel prt. ISCSI-1 and ISCSI-2 prt grups were then bund t the VMware ESXi sftware ISCSI adapter. All paths t the strage array were cnfigured t utilize the native VMware NMP f Rund Rbin t distribute the lad f the VDI desktps ver all paths fr all vlumes. A single VM Netwrk prt grup was added fr virtual machine cnnectivity. VMware ESXi management and vmtin netwrks utilized vswitch0 and the 4 prt Bradcm nbard NICs. NIC0 was active fr management and NIC1, 2, 3 were set t standby in case f NIC0 failure. The vmtin netwrk cnsisted f the remaining 9

10 3 NICs. NIC1, 2 and 3 all had separate prt grups and VMkernal prts setup and dedicated fr Vmtin. By setting all 3 NICs, VMware ESXi 5 allws aggregatin f the 1Gb NICs t prvide maximum thrughput fr vmtin activities. VMware View 5 T prepare fr the desktp deplyment, a single virtual machine (VM) was created as the base image fr VMware View 5. This image was ptimized and cnfigured in accrdance with the VMware View Planner 2.1 installatin and user guide. Windws 7 SP1, Micrsft Office 2007 and ther business applicatins required by VMware View Planner 2.1 were installed. The VMware View Desktp Agent was installed fr management within Virtual Machine. Lastly, the VMware View Planner 2.1 setup package was installed t prepare the image fr the VMware View Planner 2.1 Lad Generatin tl. The base image then was shutdwn and a VMware snapsht f the virtual machine was created. A VMware snapsht is a requirement f VMware View Cmpser 5 linked clnes. A VMware View 5 autmated resurce pl (Pl1) with 500 VMware View Cmpser linked clne virtual machines was created. An identical autmated pl f 500 virtual machines was created fr (Pl2). The snapsht image was then autmatically clned t each specific replica disk fr each pl. After the replica was cpied t its respective VMware Datastre, the VMware View Cmpser linked clne virtual machine creatin prcess began. Figure 2. Virtual disk relatinship per vlume 10

11 Figure 3. VMware ESXi 5 datastre layut per pl VMware View 5 VMware View 5 Pl 1 VDI-P1-VM1 C: D: P1-Delta-1 P1-Delta-1 P1-Delta-2 P1-Delta-2 P1-Delta-3 P1-Delta-3 P1-Delta-4 P1-Delta-4 P1-Delta-5 P1-Delta-5 Z: P1-Replica-1 P1-Replica-1 P1-User-1 P1-User-1 P1-User-2 P1-User-2 P1-User-3 P1-User-3 P1-User-4 P1-User-4 P1-User-5 P1-User-5 VMware View 5 Pl 2 VDI-P2-VM1 C: D: P2-Delta-1 P2-Delta-1 P2-Delta-2 P2-Delta-2 P2-Delta-3 P2-Delta-3 P2-Delta-4 P2-Delta-4 P2-Delta-5 P2-Delta-5 Z: P2-Replica-1 P2-Replica-1 P2-User-1 P2-User-1 P2-User-2 P2-User-2 P2-User-3 P2-User-3 P2-User-4 P2-User-4 P2-User-5 P2-User-5 Windws 7 The virtual desktps platfrm fr all tests was Windws 7 Prfessinal 32-bit with SP1. Each VM was cnfigured with ne vcpu and 1024Mb f memry. Micrsft Office 2007 was installed, as well as the applicatins required fr VMware View Planner. The template desktp was ptimized using the best practices frm the View Planner installatin guide and VMware View and Windws 7 ptimizatin guide. Antivirus N antivirus prduct was utilized within the VMs. Intrducing traditinal antivirus sftware may dramatically increase the I/O lad f the VM. Special cnsideratin shuld be taken when implementing antivirus prgrams in a virtual envirnment. Using virtualizatin-aware antivirus applicatins such as VMware vshield Endpint r Trend Micr may reduce the I/O requirements within the virtual envirnment. Strage Center cnfiguratin The Dell Cmpellent Strage Center SAN was designed t maximize perfrmance in a VDI envirnment. A pl f disks was created with tw tiers f strage within the SAN. The first tier cnsisted f three 200GB SSDs, and the secnd tier cnsisted f frty-eight 10K 900GB SAS drives. Making 1 SDD and 2 10k 11

12 drives ht spares left a ttal f 2 active 200GB SSD drives and 46 active 10k 900GB drives. Strage Center was running firmware versin during the test. Tw custm strage prfiles were created t accmmdate the perfrmance characteristics f the tw drive types used in testing. The first custm strage prfile created was the VDI-Replica prfile (Figure 5). It was applied t all replica vlumes t lck in the replica images n the Tier1 SSD. The secnd custm strage prfile that was created was VDI-SteadyState prfile (Figure 5). This prfile bypasses the SSD tier1 and directs all writes t the 10k tier f disks. (Fr details n creating custm strage prfiles, see the Dell Cmpellent Administratin Guide). Figure 4. VDI-SteadyState strage prfile VDI-Replica Strage prfile Data Prgressin, replay technlgy Data Prgressin is the technlgy that allws the Dell Cmpellent Strage Center t dynamically mve 2Mb pages f strage between tiers f strage r between different RAID types amng the same tier level. Data Instant Replays are the snapsht cmpnent f a Dell Cmpellent Strage Array. Data Instant Replays are unique because they utilize a technlgy f redirect at write instead f the traditinal cpy n write technlgy. At a very high level when a Replay is taken f a vlume, all active 2Mb pages are marked as read-nly. All pages that are marked as read-nly will stay read-nly until either a new write is directed at a specific page r the data in the specific page is deleted. Data Prgressin is dependent upn replays t maximize strage efficiency. Data Prgressin, which is a daily lw pririty scheduled activity, analyzes all vlumes and determines which pages have the read/-nly attributes. Data Prgressin dynamically mves the read-nly pages t a mre efficient RAID level typically RAID 5-9 r RAID Data Prgressin is a pwerful tl fr VDI efficiency. Because VDI is traditinally write-intensive, the Dell Cmpellent Strage Array is a perfect fit. Dell Cmpellent is very efficient with writes because the default RAID type f all vlumes is RAID 10. RAID 10 ffers significant write perfrmance because f a 12

13 minimal write penalty. After a replay is taken f the vlume, Data Prgressin will then mve the newly created pages t RAID 5 r RAID 6. Because reads frm RAID 5 r RAID 6 nt incur a read penalty read perfrmance frm RAID 5 r RAID 6 are cmparable t reading data frm RAID 10. A replay prfile named VDI was created in the Dell Cmpellent Strage Center GUI. The replay prfile schedule was setup t take a replay daily at 6 p.m. (See Figure 6) The VDI replay prfile als expired after nly 25 hurs. Setting an expiratin f 25 hurs allws fr maximum perfrmance frm Data Prgressin and allws fr minimal disk space t be cnsumed. The replay prfile was then assciated t all VMware View Datastres. (See Figure 3) Figure 5. Replay creatin Figure 7 shws ne f the VMware View Delta vlumes used fr testing. Each Delta vlume was utilized by apprximately 100 VDI desktps. The chart shws the vlume cnsumptin statistics after a View Planner 2.1 wrklad test had finished. Within this vlume, 54.07GB f data resided n the 10k Tier3 drives cnfigured as RAID 5-9. The remaining data resided n RAID 10 with Fast Track (the uter 20% f the disk) r RAID 10 standard. Because f Dell Cmpellent ability t ingest all writes at RAID10, 33GB f data was written thrughut the day during the wrklad test n this single vlume with 100 VMs running n it. After the View Planner wrklad cmpleted, anther replay was t be taken f this vlume. Data Prgressin will mve thse RAID 10 pages nt RAID 5 and ld expired RAID 5 pages will expire and be reallcated t the free page pl. 13

14 Figure 6. Replay statistics pst wrklad run Testing results Testing fr this reference architecture invlves measuring tw perfrmance indicatrs. The first indicatr is the amunt f IOPS cnsumed during a bt strm. The secnd indicatr measures the perfrmance f all 1,000 desktps during simulated user lad. Bt test The bt test represents a wrst-case scenari where all 1,000 virtual desktps are pwered n simultaneusly. This situatin wuld nt take place during nrmal VMware View peratin due t VMware View s pwer management functinality. Hwever, it is plausible that many desktps will need t be started quickly in a prductin envirnment, pssibly when recvering frm an utage. A bt strm als prvides a gd measurement f verall back-end strage perfrmance. In ur testing, the length f the bt strm was measured by examining the duratin f sustained high IOPS during a simultaneus pwer n f all 1,000 virtual desktps. In the cnfiguratin utlined abve, with the replica image residing n SSDs, and all ther read-write peratin cming frm 10k SAS drives, the average length f the bt strm was six minutes. During the bt strm, ttal frnt end IOPS ranged frm 32,000 t 35,000. Seventy percent f all IOPS came frm the read-nly SSD tier, while the remaining 30% came frm the 10K SAS tier. Read latency n the delta vlumes spiked t 30ms. Write latency averaged 35ms during the same time. This high latency is cmmn because f the limited number f 10k drives required t meet the steady state requirements f the user wrklad. Because nly 30% f the ttal IOPS required fr the bt strm came frm these 10k drives, the latency during the bt strm was acceptable. There was n measurable read latency n the SSD tier f strage. 14

15 The graphs belw shw an example f ne f the bt tests perfrmed with 1,000 virtual desktps. As the graphs shw, the majrity f reads came frm SSD/replica disk during the bt strm. This is due t the read-nly replica data n the master image residing n SSD disks. There is als an initial read spike n the 10K disk tier with the number f writes increasing as the systems are bted. After the bt strm, the number f writes surpasses the number f reads. (Figure 8) shws the verall IOPS/sec during the 1,000 virtual desktp bt strm. The yellw line is verall IOPS/sec, the purple line is read IOPS/sec and black line is write IOPS/sec. Ntice the dependency n reads during the bt strm prcess. (Figure 9) shws the SSD disks IOPS/sec during the 1,000 virtual desktp bt strm. The yellw line is verall IOPS/sec, the purple line is read IOPS/sec and black line is write IOPS/sec. Ntice that the SSD disks are prviding apprximately 70% f the IOPS/sec during the bt strm perid. Als nte that n writes were ccurring at the SSD tier f disks. (Figure 10) shws the 10k disks IOPS/sec during the 1,000 virtual desktp bt strm. The yellw line is verall IOPS/sec, the purple line is read IOPS/sec and black line is write IOPS/sec. Ntice that the 10k disks are prviding apprximately 30% f the IOPS/sec during the bt strm perid. Althugh 30% may seem like a small dependency, under sizing the 10k disks may present a bttleneck during bt and lgin strms. In this scenari the 10k disks d prvide adequate IOPS/sec, but latency n the 10k disks was relatively high at 30-40ms during the bt strm. 15

16 Figure 7. Ttal IOPS during bt strm Figure 8. SSD IOPS during bt strm 16

17 Figure 9. 10K IOPS during bt strm 17

18 Lad test The gal f the lad test is t identify the impact f the user wrklad n the Dell Cmpellent Strage array. The lad test was perfrmed against the 1,000 desktps using VMware View Planner 2.1. VMware View Planner 2.1 was run utilizing the lcal mde ptin. The lcal mde peratin starts 64 virtual desktps per minute until the required (1,000) virtual machines check-in with VMware View Planner. Once all 1,000 virtual desktps successfully check-in, the lad test begins n the 1,000 virtual desktps. View Planner scring methdlgy When the View Planner wrklad generatr is run accrding t specific requirements, it prduces a View Planner scre. This scre indicates hw many users cncurrently running a standardized set f peratins a particular strage infrastructure can supprt. While this standardized set f peratins is representative f many real wrld deplyments, sme users might have different needs. The custm applicatins feature allws these varying lads t be mdeled and is designed t address this exact use case. Hwever, because f the lack f standardizatin, runs using the custm applicatins feature may nt be used t generate a cmpliant View Planner scre. View Planner wrklad run phases During a wrklad run each desktp virtual machine ges thrugh three phases: Ramp Up (ne iteratin) Steady State (at least three iteratins) Ramp Dwn (ne iteratin) During an iteratin f the user wrklad, View Planner reprts the latencies fr each peratin perfrmed within each virtual machine. Requirements fr cmpliant run In rder fr a wrklad run t be cnsidered cmpliant, it must meet the fllwing requirements: It must run all f the standard View Planner applicatins and n ther applicatins. The think time fr View Planner must be set t 20 secnds. It must cntain at least five iteratins (including Ramp Up and Ramp Dwn). At least 95% f the respnse times during Steady State must be 1.5 secnds r less. View Planner Wrklad Cnfiguratin Users - 1,000 Wrklad type Lcal Mde Iteratins 8 Ramp-up Time - 1 secnd 18

19 Think Time 20 secnds All VMware View Applicatins MS Outlk, MS Excel, MS Wrd, MS PwerPint, MS Internet Explrer, Adbe Acrbat, 7zip, Mzilla Firefx, Windws Media Player VMware View Planner 2.1 wrklad results The wrklad test was a lcal mde run with VMware View planner set t 8 iteratins, a think time f 20 secnds, and a ramp up time f 1 secnd. All required VMware View Planner applicatins were tested during this wrklad. The 8 iteratins that made up the wrklad tk apprximately 10 hurs t cmplete. The average IOPS/sec fr the entire test including bt and lgin was apprximately 6,450 IOPS. The read-write % during the wrklad was 10% read 90% write. The chart belw shws the thrughput, read, write IOPS during the duratin f the wrklad test. The initial IOPS burst symblized VMware View Planner starting all 1,000 virtual desktps. VMware View planner steady-state wrklad begins at the apprximately 16:00 mark. VMware View Planner running in lcal mde fr 1,000 desktps reprted a successful passing scre. The 95th percentile respnse time fr the test was nly.65 secnds. VMware View Planner 2.1 requires the 95 th percentile applicatin respnse time be at r belw 1.5 secnds. Figure 10. IOPS with View Planner wrklad 19

20 Functinal IOPS Functinal IOPS are imprtant with VDI due t the high write requirement f virtual desktps. Sme estimates put the number f writes in a VDI envirnment up t 90% f all IOPS. As shwn in the example abve, the steady-state IOPS read-write percentage was 10/90. This can affect the number f IOPS available due t the write penalties assciated with different RAID types. Write penalties are assigned t RAID levels based n characteristics f their write activity. Fr example, with RAID 1 r 10, data is written nce and read nce t verify each write. This cnsumes tw raw IOPS, s RAID 1 and 10 are assigned a write penalty f tw. Likewise, RAID 5 with 5 drives has a penalty f 5. The write penalty increases with the number f drives in the RAID set. In a planning phase f ur wrklad testing we ran a single virtual machine thrugh the VMware View Planner wrklad. An average f 4.5 IOPS/sec was bserved while running the VMware View Planner wrklad. 4.5 IOPS X 1000 VM s = 4500 IOPS. Using the functinal IOPS calculatin, a ttal f 48 drives was determined t prvide adequate disk IOPS. T calculate functinal IOPS, the number f raw IOPS are factred with the percent f reads and writes alng with the RAID penalty. The frmula fr calculating functinal IOPS is expressed as: Functinal IOPS=((Raw Strage IOPS*Write %)/RAID Write Penalty)+(Raw Strage IOPS*Read %) In the example belw we will use the frmula t figure ut the needed disks fr ur VMware View Planner 2.1 wrklad. Frty eight 900GB 10K drives in a RAID 10 cnfiguratin with 90% write t 10% read rati will prvide 4224 functinal IOPS. Functinal IOPS=((7680*90%)/2)+(7680*10%) In cmparisn, if the abve were changed t RAID 5 instead f RAID 10, the functinal IOPS wuld be Functinal IOPS=((7680*90%)/5)+(7680*10%) Fr mre infrmatin n functinal IOPS in a VDI envirnment, see the Dell Cmpellent dcument Functinal IOPS in VDI with Dell Cmpellent. 20

21 Cnclusin Based n the test results, the strage requirements fr 1,000 desktps shuld be built t supprt 4,500 IOPS. Hwever, t accurately size a strage system the percentage f write IOPS and the RAID penalty fr thse writes must be factred in. Adjusting fr RAID penalty will give the functinal IOPS required when prvisining data strage. During the lad test, averages f 10% f the IOPS were read; while the remaining 90% were write. With the cnfiguratin utlined in this dcument, all write IOPS ccur at RAID 10. This is the default fr all writes n a Dell Cmpellent Strage Center SAN. RAID 10 has a RAID penalty f tw, meaning it takes tw raw IOPS t perfrm a single write. Factring the RAID penalty in the calculatin belw, we can cnclude that it will take 7,680 raw IOPS t supprt 1,000 desktps. Functinal IOPS = ((7680*90%)*2)+(7680*10%) T meet the read-write requirements using 10K SAS drives, the test team estimates IOPS per drive t be 160. Given 160 IOPS per 10K SAS drive, it wuld take 48 drives t supprt a 1,000 user envirnment during nrmal peratin. In sme envirnments, there may be a requirement t supprt aggressive bt strms, such as what may be experienced at the beginning f the wrkday while users lg in. In ur tests, the IOPS requirement increases up t 36,000 during a bt strm with the majrity f IOPS being read. At 160 IOPS, it wuld take ver K drives t supprt this number f IOPS during a bt strm. The testing team was able t reduce the number f drives t supprt a bt strm by placing the replica image nt SSDs during the tests. The number f drives can be determined by ttal capacity f required replica images, as the SSDs can handle nearly 25,000 read IOPS per drive. Latency is als an imprtant cnsideratin in a VDI envirnment. During the lad tests, there was n measurable read latency n the SSD drives. The baseline write latency fr the 10K disk pl was 3ms, and the read latency baseline was 8ms fr the same pl f 10k disks. The preceding tests used VMware View 5 with VMware View Cmpser Linked Clne desktps. These desktps are nt persistent and typically rely n prfile management strategy t deliver user-specific data t the desktp. As such, we did nt factr in space requirements fr user data in ur testing. Hwever, this shuld be cnsidered when implementing a VDI envirnment. 21

22 Reference materials The Dell Cmpellent Administratin Guide is available n the Dell Cmpellent Custmer Prtal VMware VMware View 5 Dcumentatin VMware View Optimizatin Guide fr Windws 7 Functinal IOPS in VDI with Dell Cmpellent Dell Cmpellent Strage Center Best Practices Guide with VMware vsphere 5.x th%20vmware%20vsphere%205.x.pdf Dell Cmpellent Strage Center Users Guide Appendix A Example PwerShell Answer file 22

23 Test System Cmpnent Details Hardware Versin Quantity DELL M1000e Blade Enclsure DELL M8024-k Blade I/O Mdule Brcade M5424 Blade I/O Mdule DELL M710HD Blade Server DELL Cmpellent SC8000 Cntrller DELL Cmpellent 24 bay 2.5 inch Enclsure N/A 3 DELL Cmpellent 10k 900GB 6Gb SAS Hard Drives N/A 48 DELL Cmpellent SSD 200GB 6Gb SAS Hard Drives N/A 3 DELL Gb Ethernet Switch