Webinar: Don't believe the hype, you don't need dedicated storage for VDI
Storage for VDI
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Transcript of Storage for VDI
Storage for VDI
Or why storage vendors love VDI
VDI Looks Ready To Take Off
When will you deploy VDI?
3 Months 3-6 Months6-9 Months 9-12 Months12+ Months
Have you started a VDI pilot?
54%
46% Yes
No
Source: VIBriefing survey March 2012
But There’s a Disconnect
Reasons for VDI
43%
Better Endpoint ManagementLower cost"Cloud"Security
Reasons for VDI stall
31%
29%
22%
19%
Cost Performance
Software Licensing Storage Cost
Source: VIBriefing survey March 2012
Desktop Virtualization Expenses
4
Source: Gartner Dataquest
41%24%
8%8%
1%
Everyone’s Talking VDI
• 76% are choosing VDI to:– Save Costs– Improve management
• 54% project total cost <$500– One writer claimed <$200 VDI cost
• 80% Prefer persistent desktops for knowledge workers
Virsto sponsored survey of 500 IT professionals 3/2012
The Sad Truth
• Most success stories are task workers– Call centers, healthcare, Etc
• Much of your desktop support is user support• Enterprise storage is expensive• VDI creates high IOP density• According to that same Virsto study, 46% of
the VDI projects are stalled – Because of performance and/or cost
VDI and Storage
• Desktop disk:– 30-40GB, 100 IOPS – 200 desktops = 6TB, 20,000 IOPS– 100+ 15K RPM drives RAID 10
• Windows 7 with AV 2x IOPS of WinXP• VDI user steady state IOPS
– Light 6-12– Power 5-40
• But you need to plan for peak
VDI Presents Unique Workloads
• Highly variable but coincident (boot/login in morning)• Steady state 50+% write
200 Desktop VDI Storage Performance Demands
Anatomy of a Linked Clone• Master Replica
– Common data
• Delta Disk – Accumulates changes
from master per clone
• Disposable– Swap, Temp Etc.
• Persistent (Opt)– Additional drive letter– Permanent data
Plus The Persona• Roaming Profile
– Redirected \USERS\RacerX– Copied to C: on login– Issues:
• Long login/logout• Disk space consumption
– Especially on shared systems
• More granular approaches like View Persona Management better
About Desktop Persistence
• Non-Persistent desktops– Delta disk discarded at shutdown/logout– For task workers
• Persistent linked clones– Preserve delta disk, persistent disk– Allows centralized patching via re-composition
• Full clones– Complete virtual PC
Living with Linked Clones
• Constant growth– At VMware 1GB/user/week– Can overwhelm initial savings
• IOP concentration on Master Replica– Good use of a little flash
• Recomposing resets non-persona data– Installed Applications
• Browser plugins, Etc.
Basic VDI Recommendations
• Use linked clones or deduped full clones• Put master image on flash (many reads)
– More IOPS to Delta during steady state though
• Separate differencing data– User profiles– Swaps
• Try to avoid IOPS to spinning disk– Use RAM or flash
• $/IOP not $/GB
View Storage Accelerator
• AKA Content Based Read Cache• Up to 2GB RAM as a read cache• Content Based means cache is deduped • Most effective at boot
– Cause that’s when lots of common data reads
View Storage Accelerator vs. Boot Storm
And vs. AV Scan Storm
Atlantis ILIO
• Dedupes data• Accumulates writes to 64KB• Larger read and write RAM Cache• Can install on each host or Top of Rack
The Good News
• VDI Images are just desktops– HA may be less important than performance– I would use a single controller Flash system
• All the storage startups are validating VDI solutions
• Local storage could be an answer– Especially for non-persistent clones– Consider local SSD, SSD caching RAID
controller
Things to look for in VDI Storage
• Substantial flash component – 10% or more– All flash for cast of thousands
• Good snapshots– EG: Nimble, TinTri, NetApp
• VAAI Xcopy integration• Data Deduplication
– Greenbytes, Pure, Astute for all flash– TinTri, Tegile, Nexgen hybrids
Server Flash Caching Advantages
• Take advantage of lower latency– Especially w/PCIe flash card/SSD
• Data written to back end array– So not captive in failure scenario
• Works with any array– Or DAS for that matter
• Allows focused use of flash– Put your dollars just where needed– Match SSD performance to application
• Politics: Server team not storage team solution
Server Side Caching State of The Art
• Proximal Data, Flashsoft (Sandisk) install in hypervisor– But are write through cache
• Speeds reads but passes writes through
• Most others are server only (agent based)• Write back is coming
– Will write to SSD in n servers (n=2-3)– Will require low latency net – PernixData 1st more coming
Full Clones and Deduplication
• Full clones manage like desktops– Good news if you manage desktops
• But most people don’t use Kace or LANdesk
• Full clones are fully persistent • Deduplication reduces swap space too
– 100 new linked clones = 200GB swap reserve
• Flash eliminates read performance penalties• Inline better than post process for live data
The Don’ts
• Don’t use RAID-5 spinning disks for VDI– VDI workloads have lots of small writes– RAID-5 amplifies 3-6:1
• Expect an all disk solution to serve >50 users– Conventional wisdom = dedicated storage
• Expect $100/user costs• Limit your options to established
vendors/products
Questions and Contact
• Contact info:– [email protected] – @DeepStoragenet on Twitter