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More IOPS Please
DRMCs VMware View Implementation Using
              Nexenta

             Keith Brennan
             October 2011



                                          S
Delano Regional Medical
        Center

            S   156 bed community hospital in
                central California.

            S   Four satellite clinics.

            S   Only hospital in a 30 mile
                radius.

            S   Serves approximately 60,000
                people spread over several
                communities.

            S   80%+ of our patients are Medi-
                Cal or Medicare.
                S Government doesnt pay
                   well.
DRMCs Clinical Staff
The Great Directive of 2009


S Need to deploy 150 new desktops in support
  of a Clinical Documentation implementation.
S Do it as cheaply as possible.

S Oh, by the way, youre losing an FTE due to
  budget cuts.
Never let a good crisis go to
     waste.                     Rahm Emmanuel




S Used this Opportunity to justify moving to VDI.
  S Users resistant to using something other than a traditional
     desktop.
     S   Perceived lack of freedom.
     S   Perceived increase in Big Brother.

S Why I wanted the transition to VDI
  S Ease of management.
  S We had a set, well defined, integrated, desktop experience.
  S Wanted a way to deliver the same experience in a controlled
     manner to a myriad of devices. IOS, Android, etc.
I Need Storage!

S My Existing EMC CX500 was barely cutting it for 3 ESX
  hosts w/ a combined 32 VMs.

S Lots of people on the Virtualization forums liked NetApp.

S NetApp had just published a white paper on a 750 View
  virtual desktop deployment on a FAS 2050a.
  S Near normal desktop load times.
  S Seamless user experience.
Well Thats Timely!


S The next week another vendor calls letting me know that
  IBM is running a huge storage sale.

S It includes their N series of network attached storage.
  S Rebadged NetApps.

S Three weeks later a N3600, a rebadged NetApp 2050a,
  arrives.

S It is setup identically to the VDI whitepapers setup.
Implementation Guidelines

S Linked clones are to be used whenever possible.
   S Ease of maintenance
   S Ease of provisioning

S No user data to be stored on the VMs.

S Significant patching shall be done through the Golden Image
  and VMs will be re-provisioned with using the updated image.

S AV will run on the VMs but only in real-time scan mode. No
  scheduled system scans.
Initial Testing

S Two Hosts with 25 VMs each.
   S One connected to the N3600 via ISCSI
   S The other via NFS.

S Test lab of 25 thin clients.

S Good performance.
   S Equivalent to a desktop of the previous generation.
   S Quick user logins due to the VMs being always on and waiting.
   S The N3600 is maintaining low utilization.
   S NFS and ISCI exhibit similar speed.
Go Live!

S Five additional ESX Hosts are deployed.
  S Each hosts ~25 VMs
  S Current setup gives me N+2 host redundancy.

S For the first week everything looks good.

S User complaints are primarily with the clinical application.

S N3600 is handling it well. Running at about 35%
  utilization.
  S ~1.5k IOPs/Sec of regular background chatter.
  S VMs report average latency of 12ms.
Disaster!
            For me they happen seem to happen in threes.




S First AV engine update happens 1 week after go live.
  S AV server pushes it to all clients at once.
  S The simultaneous update of all the View VMs forces the
    SAN to a crawl for 3 hours.
  S Users complain that the Virtual Desktops are unusable.
  S Temporarily corrected the problem by only allowing the AV
    to update 3 machines at once.
  S This worked like a champ until a dot version update on the
    AV server a month later broke that setting.
     S   Another 3 hour downtime.
Disaster (cont)


S Three days later a helpdesk tech forces the simultaneous
  reprovisioning of 60 of the View VMs at once.
  S Was applying an application patch.
  S Was trained not to restart more than 5 VMs at once.
     S   That obviously didnt stick!
  S That was another hour of the SAN crawling.
  S Once again, users complain that the system was unusable
     during this time.
Disaster! (yet again)

S .net 3.5 service pack is approved for deployment.

S SP is large. >100mb.

S Set to deploy starting at 2am and only on restart.
  S At 04:15 four VMs restart within one minute of each other.
  S N3600 starts to lag.
  S Users seeing their system running slow decide to restart.

S At 5am I get the call regarding the issue.

S I immediately disabled the SP deployment.
  S Still took an hour for the N3600 to catch up.
My Users Arent Happy
Whats Going On???


         S Oh $41+
          S General use chatter is
            eating my bandwidth.
          S N3600 CPU utilization is
            regularly now above
            50%.
          S Disk utilization rarely
            drops below 40%.
          S Average disk latency
            >18ms.
I Have a Problem

S   Im maxing performance with just day to day operations.
S IBM has verified that the appliance is functioning
    properly.
    S In other words, this is all Im going to get out of it.
    S Adding disks might help some, but too costly!
      S Additional Tray would be $15k!
      S SAS drives to populate it are almost $1k each!
      S Still have CPU limitations.
      S NIC Limitations (2  1gbe links per head)

S Did I mention that I have no money left in the budget?
Nexenta to the Rescue


S Had just installed Nexenta Core for my home file server.

S Time to find some hardware:
  S Pulled a box out of the View cluster.
  S Installed six Intel SSDs.
  S Installed Nexenta Core. (yeah, I know.. EULA..)
  S Created the volume and shared via NFS.
  S The next day my poor brain figured out that I could have just
      done a Nexenta VM. Doh!

S Over the next week I migrated half the virtual desktops over.
Its like Night and Day

S Average latency drops
  from 18ms to 2ms.
S Write throughput
  quadruples.
S Read throughput
  doubles.
S 20x improvement on 4k
  iops!
They Like me Again!
Time For a Full Nexenta
         Implementation

S I was able to secure $45k capital for the next year.
  S Normally this would just draw laughter when talking about
      storage.

S I also intend on replacing the existing EMC.
  S Annual maintenance too costly.
  S I despise the fact that I have to call them out every time I want
      to connect a new piece of hardware to it.

S Still some questioning from higher-ups on this whole open-
   storage thing.
Final Solution Hardware

S 2x Supermicro dual Xeon servers with 96gb ram.

S 1x DataOn 1600 JBOD
  S Houses twenty one 1tb nearline SAS drives.

S 1x DataOn 1620 JBOD
  S Houses seventeen 300gb 10k rpm SAS drives

S 2x Stec ZeusRam

S 8x 160gb Intel 320 SSDs
Hardware Diagram
Why DataOn?


S Disk Shelf Manager
   S One thing Nexenta lacked
     was a way to monitor the
     JBoDs
   S How could one of my techs
     know how which drive to
     pull?

S Intuitive slot lighting.

S Theyre responsive even
   after the sale is made!
Why Nexenta?


S Its good to have on demand support.
  S I am the only member of our technical staff that has a basic
    understanding of storage architectures.
  S I like to have the ability to go on vacation from time to time!

S Its good to have experts for unique problems.

S Regular tested bug-fixes.

S Its always nice to have someones neck to wring!
The End Result

S 2ms latency.

S 500 mb/s reads

S 200 mb/s writes

S Happy Users!

S Note: Benchmark was
  done on production
  system with 175 active
  VMs.
To Dedup or Not to Dedup


S Dedup can give you huge storage savings.
  S I had 14x Dedup ratio on my VDI volume.

S Inline dedup saves on disk write IO.
  S Itll still hit the ZIL, but wont be written to disk if it is
     determined to be duplicated data.
     S   Instead of a 4+kb write you get a sub 256 byte metadata write.
To Dedup or Not to Dedup

S Ram Hog!
  S For good performance you need enough ram to store the
      dedup table.
      S   Uses ARC for this, which means you will have less room for
          cached data.

S Potential for hash collision.
  S Odds are astronimcal, but still a chance for data corruption.

S Dedup performance penalty.
  S Small IOPS suffer.
Dedup Perfomance Penalty

 Dedup Enabled   No Dedup
Is Dedup Worth it?

S If youre using a Golden Image - No.
  S VMDC Plugin provides great efficiency by only storing one
    copy of the Golden Image vs one for each pool of VMs.
  S Compression is virtually free and will do a good job of
    making up the difference in the new blocks.
  S Disk is cheap.

S If youre doing a bunch of P2V desktop migrations -
  Maybe.
  S If the desktops are poorly configured, or have other aspects
    that can cause excessive I/O than no.
  S If the desktops are similar and large, then sure.
Compression


S Use it. Unless youre using a 5 year old processor, there
  will be no noticeable performance hit.
  S On by default in Nexenta 3.1
  S Compresses before write. Saves disk bandwidth!
Cache is Key!


S Between the the 70gb of arc and 640gb of l2arc the read cache
  is hit almost 98% of the time!




S This equates to sub 2ms average disk latency to the end user.

S Beats the crud out of the >15ms average latency of the N3600!

S Know your working set. You could get away with a lot
  smaller or need a lot larger cache.
Latency Under Stress
Gig-E vs TenGig-E
Gig-E vs TenGig-E


S Obvious differences in maximum throughput.

S Small IOP differences are mainly attributable to network
  latency differences.

S If youre stuck with Gig-E go use 802.3ad trunk groups.
  S Still stuck with 100 mb/s throughput but no one ESX host
     will saturate the link for the rest.
Gig-E vs TenGig-E - User
            Perspective

S Average time from the Power On VM command being
    issued to the user is able to login:
    S 10gbe: 23 seconds
    S 1gbe: 32 seconds

S Time from when user presses login button until the
    desktop is ready to use:
    S 10gbe: 5 seconds
    S 1gbe: 9 seconds

*Windows 7, 2 procs, 2gb ram, DRMCs Standard Clinical Image
Final Thought  All SSD
            Goodness

S For deployments of Linked Clones or VMs off of a Golden
   Image.

S Allows you to get rid of the L2ARC.

S Use a good ZIL Device (STEC ZeusRam, DDRDrive)
  S Allows for sequential writes to the SSDs in the pool.
      S   Saves on write wear which is a SSD killer.
          S My first test box with the x25m SSDs started suffering after
             about 3 months.

S If you want HA you have to use SAS drives.
Takeaway:

Latency is
  Key!!
             S
keith@drmc.com
 661-721-5650
  Feel free to contact me.




                             S

More Related Content

OSS Presentation DRMC by Keith Brennan

  • 1. More IOPS Please DRMCs VMware View Implementation Using Nexenta Keith Brennan October 2011 S
  • 2. Delano Regional Medical Center S 156 bed community hospital in central California. S Four satellite clinics. S Only hospital in a 30 mile radius. S Serves approximately 60,000 people spread over several communities. S 80%+ of our patients are Medi- Cal or Medicare. S Government doesnt pay well.
  • 4. The Great Directive of 2009 S Need to deploy 150 new desktops in support of a Clinical Documentation implementation. S Do it as cheaply as possible. S Oh, by the way, youre losing an FTE due to budget cuts.
  • 5. Never let a good crisis go to waste. Rahm Emmanuel S Used this Opportunity to justify moving to VDI. S Users resistant to using something other than a traditional desktop. S Perceived lack of freedom. S Perceived increase in Big Brother. S Why I wanted the transition to VDI S Ease of management. S We had a set, well defined, integrated, desktop experience. S Wanted a way to deliver the same experience in a controlled manner to a myriad of devices. IOS, Android, etc.
  • 6. I Need Storage! S My Existing EMC CX500 was barely cutting it for 3 ESX hosts w/ a combined 32 VMs. S Lots of people on the Virtualization forums liked NetApp. S NetApp had just published a white paper on a 750 View virtual desktop deployment on a FAS 2050a. S Near normal desktop load times. S Seamless user experience.
  • 7. Well Thats Timely! S The next week another vendor calls letting me know that IBM is running a huge storage sale. S It includes their N series of network attached storage. S Rebadged NetApps. S Three weeks later a N3600, a rebadged NetApp 2050a, arrives. S It is setup identically to the VDI whitepapers setup.
  • 8. Implementation Guidelines S Linked clones are to be used whenever possible. S Ease of maintenance S Ease of provisioning S No user data to be stored on the VMs. S Significant patching shall be done through the Golden Image and VMs will be re-provisioned with using the updated image. S AV will run on the VMs but only in real-time scan mode. No scheduled system scans.
  • 9. Initial Testing S Two Hosts with 25 VMs each. S One connected to the N3600 via ISCSI S The other via NFS. S Test lab of 25 thin clients. S Good performance. S Equivalent to a desktop of the previous generation. S Quick user logins due to the VMs being always on and waiting. S The N3600 is maintaining low utilization. S NFS and ISCI exhibit similar speed.
  • 10. Go Live! S Five additional ESX Hosts are deployed. S Each hosts ~25 VMs S Current setup gives me N+2 host redundancy. S For the first week everything looks good. S User complaints are primarily with the clinical application. S N3600 is handling it well. Running at about 35% utilization. S ~1.5k IOPs/Sec of regular background chatter. S VMs report average latency of 12ms.
  • 11. Disaster! For me they happen seem to happen in threes. S First AV engine update happens 1 week after go live. S AV server pushes it to all clients at once. S The simultaneous update of all the View VMs forces the SAN to a crawl for 3 hours. S Users complain that the Virtual Desktops are unusable. S Temporarily corrected the problem by only allowing the AV to update 3 machines at once. S This worked like a champ until a dot version update on the AV server a month later broke that setting. S Another 3 hour downtime.
  • 12. Disaster (cont) S Three days later a helpdesk tech forces the simultaneous reprovisioning of 60 of the View VMs at once. S Was applying an application patch. S Was trained not to restart more than 5 VMs at once. S That obviously didnt stick! S That was another hour of the SAN crawling. S Once again, users complain that the system was unusable during this time.
  • 13. Disaster! (yet again) S .net 3.5 service pack is approved for deployment. S SP is large. >100mb. S Set to deploy starting at 2am and only on restart. S At 04:15 four VMs restart within one minute of each other. S N3600 starts to lag. S Users seeing their system running slow decide to restart. S At 5am I get the call regarding the issue. S I immediately disabled the SP deployment. S Still took an hour for the N3600 to catch up.
  • 14. My Users Arent Happy
  • 15. Whats Going On??? S Oh $41+ S General use chatter is eating my bandwidth. S N3600 CPU utilization is regularly now above 50%. S Disk utilization rarely drops below 40%. S Average disk latency >18ms.
  • 16. I Have a Problem S Im maxing performance with just day to day operations. S IBM has verified that the appliance is functioning properly. S In other words, this is all Im going to get out of it. S Adding disks might help some, but too costly! S Additional Tray would be $15k! S SAS drives to populate it are almost $1k each! S Still have CPU limitations. S NIC Limitations (2 1gbe links per head) S Did I mention that I have no money left in the budget?
  • 17. Nexenta to the Rescue S Had just installed Nexenta Core for my home file server. S Time to find some hardware: S Pulled a box out of the View cluster. S Installed six Intel SSDs. S Installed Nexenta Core. (yeah, I know.. EULA..) S Created the volume and shared via NFS. S The next day my poor brain figured out that I could have just done a Nexenta VM. Doh! S Over the next week I migrated half the virtual desktops over.
  • 18. Its like Night and Day S Average latency drops from 18ms to 2ms. S Write throughput quadruples. S Read throughput doubles. S 20x improvement on 4k iops!
  • 19. They Like me Again!
  • 20. Time For a Full Nexenta Implementation S I was able to secure $45k capital for the next year. S Normally this would just draw laughter when talking about storage. S I also intend on replacing the existing EMC. S Annual maintenance too costly. S I despise the fact that I have to call them out every time I want to connect a new piece of hardware to it. S Still some questioning from higher-ups on this whole open- storage thing.
  • 21. Final Solution Hardware S 2x Supermicro dual Xeon servers with 96gb ram. S 1x DataOn 1600 JBOD S Houses twenty one 1tb nearline SAS drives. S 1x DataOn 1620 JBOD S Houses seventeen 300gb 10k rpm SAS drives S 2x Stec ZeusRam S 8x 160gb Intel 320 SSDs
  • 23. Why DataOn? S Disk Shelf Manager S One thing Nexenta lacked was a way to monitor the JBoDs S How could one of my techs know how which drive to pull? S Intuitive slot lighting. S Theyre responsive even after the sale is made!
  • 24. Why Nexenta? S Its good to have on demand support. S I am the only member of our technical staff that has a basic understanding of storage architectures. S I like to have the ability to go on vacation from time to time! S Its good to have experts for unique problems. S Regular tested bug-fixes. S Its always nice to have someones neck to wring!
  • 25. The End Result S 2ms latency. S 500 mb/s reads S 200 mb/s writes S Happy Users! S Note: Benchmark was done on production system with 175 active VMs.
  • 26. To Dedup or Not to Dedup S Dedup can give you huge storage savings. S I had 14x Dedup ratio on my VDI volume. S Inline dedup saves on disk write IO. S Itll still hit the ZIL, but wont be written to disk if it is determined to be duplicated data. S Instead of a 4+kb write you get a sub 256 byte metadata write.
  • 27. To Dedup or Not to Dedup S Ram Hog! S For good performance you need enough ram to store the dedup table. S Uses ARC for this, which means you will have less room for cached data. S Potential for hash collision. S Odds are astronimcal, but still a chance for data corruption. S Dedup performance penalty. S Small IOPS suffer.
  • 28. Dedup Perfomance Penalty Dedup Enabled No Dedup
  • 29. Is Dedup Worth it? S If youre using a Golden Image - No. S VMDC Plugin provides great efficiency by only storing one copy of the Golden Image vs one for each pool of VMs. S Compression is virtually free and will do a good job of making up the difference in the new blocks. S Disk is cheap. S If youre doing a bunch of P2V desktop migrations - Maybe. S If the desktops are poorly configured, or have other aspects that can cause excessive I/O than no. S If the desktops are similar and large, then sure.
  • 30. Compression S Use it. Unless youre using a 5 year old processor, there will be no noticeable performance hit. S On by default in Nexenta 3.1 S Compresses before write. Saves disk bandwidth!
  • 31. Cache is Key! S Between the the 70gb of arc and 640gb of l2arc the read cache is hit almost 98% of the time! S This equates to sub 2ms average disk latency to the end user. S Beats the crud out of the >15ms average latency of the N3600! S Know your working set. You could get away with a lot smaller or need a lot larger cache.
  • 34. Gig-E vs TenGig-E S Obvious differences in maximum throughput. S Small IOP differences are mainly attributable to network latency differences. S If youre stuck with Gig-E go use 802.3ad trunk groups. S Still stuck with 100 mb/s throughput but no one ESX host will saturate the link for the rest.
  • 35. Gig-E vs TenGig-E - User Perspective S Average time from the Power On VM command being issued to the user is able to login: S 10gbe: 23 seconds S 1gbe: 32 seconds S Time from when user presses login button until the desktop is ready to use: S 10gbe: 5 seconds S 1gbe: 9 seconds *Windows 7, 2 procs, 2gb ram, DRMCs Standard Clinical Image
  • 36. Final Thought All SSD Goodness S For deployments of Linked Clones or VMs off of a Golden Image. S Allows you to get rid of the L2ARC. S Use a good ZIL Device (STEC ZeusRam, DDRDrive) S Allows for sequential writes to the SSDs in the pool. S Saves on write wear which is a SSD killer. S My first test box with the x25m SSDs started suffering after about 3 months. S If you want HA you have to use SAS drives.
  • 38. keith@drmc.com 661-721-5650 Feel free to contact me. S