Stateless Reference Architecture Storage

[wlftech]

I've read numerous posts / blogs about VMware's Reference Archictecture for Stateless Virtual Desktops with VMware View 4.5.  I am trying to determine what makes the most sense given our environment and us trying to deploy 100 concurrent View Desktops at this time.  We just purchased 4 x B250 Cisco blades to run our View environment.  They have 2 x local SAS 15k 72GB drives as the SSD option cost way too much from Cisco.

Our SAN is a Compellent Series 30 with 3 disk shelves.  2 shelves are Tier 1 / 15K FC (32 Disks total ..2 are spares).  1 shelf is Tier 3 SATA.

I have thought about trying to use the storage tiering option in View to do the following:

• Local SAS 15k Drives --> Replicas
• Tier 1 SAN --> Deltas & Linked Clones
• Tier 3 SAN --> Persistent Disk & Profiles

Since our local storage is not SSD should I even be thinking about this?  If it does make sense should I RAID1+0 the 15 SAS drives to increase read performance given the replica workload?  I know the SAS drives will not provide the read performance that SSDs would...my big question is would the locally attached SAS storage be better than my shared storage?

Second option I have thought about is just using the Compellent SAN and putting all disks on shared storage.  Our SANs are not being hit hard so should I be worried about boot storms of 100 concurrent desktops which probably won't all be logging in at the same time?  If I did this setup then I would place the Replicas, Deltas / Linked Clones on Tier 1 and Persistent Disks on Tier3.

Last option I am considering is to use both of our SANs to spread the IOPS out across both?  Our other SAN is an HP EVA 4000 with 28 x 15K FC drives.  In this setup I would do the following:

• HP EVA 4000 --> Replicas
• Compellent Tier 1 --> Deltas & Linked Clones
• Compellent Tier 3 --> Persistent Disk & Profiles

Thoughts, opinions, and production experience much appreciated!

[Linjo]

Hmm, sorry to say that this will not work.

The LUN you put the Replica on needs to be accessible from all hosts that can possible run the desktop.

Thats whats the "stateless" is all about, they only used local disks and floating pools.

// Linjo

[regnak]

Hi,

Local storage without using SSD I think is a waste of time. Better put the 15K disks in your SAN as you'll be leveraging cache and other SAN optimisations. Pity Cisco make SSD so expensive. To do stateless you'll need a profile manager to allow some personalisation to take place, avoid roaming profiles! RTO virtual profiles was meant to make the 4.5 View release but was canned due to issues so if you hang back a bit you might see it in the next release. If you have the budget, you could look at an SSD appliance like a Whiptail but they 'ain't cheap either ($50K ea)! Stateless reference architecture is more a marketing ploy by VMware than a real solution at this time. For profile management now look at Liquidwarelabs profileunity if on a budget or Appsense if you're loaded!

Mike

[wlftech]

Would you still try for a stateless desktop or just use folder redirection + persistent disks?  I am starting to think this is best route to take given that the RTO software is supposed to be released in the next version.  I understand that persistent disks make their data a little harder to get to from an IT perspective compared to a file server (Profile Solution), but considering it is going to be on the SAN either way I am ok with this.

Have you had much luck redirecting Application Data?  I tried it 3-4 years ago and thought it really slowed things down and programs ran a little haywire at times?

Thanks for the info.

Michael

[regnak]

Hi,

I think Stateless is the holy grail but it has to be fast, if users perceive a lag on logon it 'aint gonna fly! For now, until things mature I'd stick with persistent disks and folder redirection because, as you point out, you can switch to a profile solution later. I would still move to a profile solution as it grants much more power over users settings than GPO's, login script and reg hacks for items such as printers, application settings and so on. 

I'd stay away for any user profile redirection including application data, with persistent disks available, as it's just not worth the hassle, to many corruption issues and performance problems as you've experienced already.

Stability, Speed and Ease of use......one day...!

Mike