Thin Provisioning Performance

[caddo]

Hi all,

if i understood right thin provisioning basically is like implementing growing disks more or less like in vmware workstation and such.

Since the disk is expanding and is not all allocated, isn't this going to affect performance?

Please someone let me know what you think!

[azn2kew]

There is a caveat using thin provisioning, you have the luxury to save disk space for not "overallocated storage" upfront but eventually it will grow so that requires you to plan your "storage capacity" if not providing sufficient disk space, while the guest is expanding in size, your systems will crash and performance will hit as well because the possibility of multiple LUNs to overlap on same disks and your guests competing for drive access. You are forcing to use smaller number of disks in this case and may experience performance bottleneck. So, depends on your storage vendor solution for thin provisioning as well.

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Regards,

Stefan Nguyen

VMware vExpert 2009

iGeek Systems Inc.

VMware, Citrix, Microsoft Consultant

[malaysiavm]

if your storage is already supporting thin provisioning, you may not really care about this. and of course, to plan and use our storage properly is always the right thing to do

Craig

vExpert 2009

Malaysia VMware Communities -

[TomHowarth]

Yes you will get a overhead from Thin Provisioning, this is stated by VMware, that said, the improvements in the IO stack should compensate for that. as to watching your Datastores more carefully, VMware have thought about that too and have introduced new Alarms to monitor LUNs. That said if your Storage Vendor already provides the ability to thin provision this feature is on the whole superfulous to your requirements.

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Tom Howarth VCP / vExpert

VMware Communities User Moderator

Blog: www.planetvm.net

Contributing author for the upcoming book "VMware Virtual Infrastructure Security: Securing ESX and the Virtual Environment”.

[admin]

Interesting Thin Disk VM = non FT VM!!!

[TomHowarth]

I had suspected as much but I had not had access to a CPU chipset to test the feature during Beta.

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Tom Howarth VCP / vExpert

VMware Communities User Moderator

Blog: www.planetvm.net

Contributing author for the upcoming book "VMware Virtual Infrastructure Security: Securing ESX and the Virtual Environment”.

[Iuridae]

Do you have the choise between using Thin Provisioning and not using it on a disk?

I have not seen vSphere yet, but looking forward to.

[cgb]

Hi Iuridae,

In case you didn't get an answer to this, yes you have a choice when:

• creating a new VM

• allocating a disk to an existing VM

You can also convert between thick/thin provisioned during a storage vmotion. So if you make a decision, and after monitoring, decide you'd like the opposite, you can perform a storage vMotion and during the process choose to convert to the thin/thick. You can go back and forth as much as you like.

Hope that helps.

Chris Bennett (cgb)

[sonvnicb]

I think thin provision not affect much performance but it only good if we have many vm on an datastorage. In our system, each vm have one LUn, i don't use thin

[ConstantinV]

According to my data, TP almost has no affect on perfomance. If you are using one VM per LUN you, of cource, don`t need it.

Starwind Software Developer

[TheGoof]

For what it's worth, we are implementing Backup Exec 12.5 (and their VMWare client) in our vSphere 4 environment and have done some testing with thin and thick provisioning; from a backup perspective, thin provisioned VM's are much faster to back up. Apparently, Backup Exec reads the entire vmdk, so a 40GB disk with 5GB used space would mean a thick drive has to read the entire 40GB while a thin provisioned drive only has 5GB to read. I haven't fully compared the VM performance itself, but the backup performance is definitely faster (at least, with Backup Exec's implementation).

[ConstantinV]

Oh, thanks for nice note! Need to check it for myself.

StarWind Software Developer

[touimet]

According to VMware there is "zero performance impact, continuous service availability and complete data integrity." when using thin provisioning.

_provisioning_datasheet.pdf

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[AWoroch]

Touimet:

Would you know of or have seen any other posts, documents, or benchmarks? I'm having a 'debate' with those I work with indicating that there is "too much of a performance hit" to use it in our environment. I'm trying to figure out how I would even go about benchmarking it - do it in the OS on the VM and try it both ways?

[DSTAVERT]

Ask those who say it causes a performance hit to disprove VMwares claim.

[touimet]

You could use several tools from the following site to run sample tests against thin and thick disks:

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Thanks, Todd

[srinivasvivek]

For other best practices please refer to my blog..

http://www.viveknadar.com/inquisitive/2009/06/vmware-tip-4-thin-provisioning-with-vsphere.html