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stormlight
Enthusiast
Enthusiast

does esx 3.5 vmfs support thin provision san lun/volumes ?

does esx vmfs support thin provision san lun/volumes ? With my Equallogics box i can present a volume/lun to a windows server with a space i think it will grow over time. say 200 gigs. However on the san side im only using 50 gigs. When i actually need the space to grow on the san i can give it what it needs and not over provision the san and while at the same time not worry about using extents.

Also with 3.5 i rember reading something about extents not being needed anymore what was that about?

thanks

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wholmes
Contributor
Contributor

According to a statement in the following knowledgebase, ESX 3.5 does not surrpot thin-provisoined disks. I am not sure if this is for VMFS and NFS, as thin-provisioned is the default deployment method for NFS.

http://kb.vmware.com/selfservice/dynamickc.do?externalId=1003874&sliceId=1&command=show&forward=nont...

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stormlight
Enthusiast
Enthusiast

I am not refering to a vmware disk as being thin provisioned. I am talking about the SAN itslef. Many SANs are able to thin provision Luns/Volumes out. For example when i create the LUN/Volume I tell my San that anyone who connects to this newly created lun will see 1TB. Normally when you do that you use the whole 1 TB. With thin provison SANs you can present 1tb to the host but in reality only carve the data that you need at the time. (Say 250 Gigs). When you get close to 250 then you tell your san to fill that virtual 1 gig with more data.

It allows you not to waste san space.

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bhadzik
Enthusiast
Enthusiast

I am not exactly sure on the actual supported nature or not, but I can confirm that it does work. Since all this is done on the SAN anyway, it is transparent to vmware. I have many customers using this feature happily.

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RParker
Immortal
Immortal

The reason you don't want to use thin provisioning is for 2 reasons. performance and management.

In an enterprise you want the best performance. When the SAN has to constantly manage the files to increase in size (and thus making more work for ESX to manage this) this impacts ALL the VM's on a LUN, because increasing space requires lots of IO.

Also the management is difficult to determine how much space your VM's are actually using, because the size only reflects physical size, not future expansion.

So thin provisioning is not done in ESX. There are ways to do it, but ESX isn't for this purpose.

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bhadzik
Enthusiast
Enthusiast

Performance can vary due to the type of SAN you use. The thin provisioning I have used does not require lots of IO, and it is transparent to ESX, thus not requiring it to do any more work. The SAN manages the thin provisioning of the volume, not ESX managing the thin provisioning of the file.

Management can be more complex because there are two different places to determine used capacity. I however think the space savings can outweigh the management overhead, but that is my opinion.

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espi3030
Expert
Expert

I know this is an old post, but was there ever a difinitive answer to this issue. I am about to move to new SAN with thin provisioning capabilities and would like to know what is VMware's official stand on this. Thank you.

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Texiwill
Leadership
Leadership

Hello,

The only way to get VMware's Official Stance on this is to contact your VMware Sales or Support Representative.

My take is if the SAN supports it and has no loss of performance, then its not a huge deal, but that depends on the SAN. I would test everything if you are performance sensitive.


Best regards,

Edward L. Haletky

VMware Communities User Moderator

====

Author of the book 'VMWare ESX Server in the Enterprise: Planning and Securing Virtualization Servers', Copyright 2008 Pearson Education.

SearchVMware Blog: http://itknowledgeexchange.techtarget.com/virtualization-pro/

Blue Gears Blogs - http://www.itworld.com/ and http://www.networkworld.com/community/haletky

As well as the Virtualization Wiki at http://www.astroarch.com/wiki/index.php/Virtualization

--
Edward L. Haletky
vExpert XIV: 2009-2023,
VMTN Community Moderator
vSphere Upgrade Saga: https://www.astroarch.com/blogs
GitHub Repo: https://github.com/Texiwill
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Aristizabal
Enthusiast
Enthusiast

Probably it is too late to reply on this thread, but I had the same question and couldn't find an official document from VMware addressing the question. So I contacted VMware support and here is what they had to say.

"If you are using ESX 3.5 Update 5 and you aren't intending on using the community sourced GUI storage vmotion plugin as we do not support the use of this plugin you are fine. As long as you use our RCLI method (page 247 on this PDF: http://www.vmware.com/pdf/vi3_35/esx_3/r35/vi3_35_25_admin_guide.pdf) which you can downloaded from our website (http://www.vmware.com/download/download.do?downloadGroup=VI-RCLI) then you shouldn't have any issues regardless of whether the disk is thin or thick provisioned."

I hope this helps.

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