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VMware Thin vs Lazy Thick vs Eager Thick disk

cpatte7372
cpatte7372 asked
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Hello Experts,

Can someone please tell me the difference between Thin vs Lazy Thick vs Eager Thick disk and which provides the best performance?

Cheers
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Commented:
The answer to your question(s)  is probably here:
http://blogs.vmware.com/vsphere/2012/03/thin-provisioning-whats-the-scoop.html
Neil RussellTechnical Development Lead

Commented:
In short....
This is the worst performance and Eager thick is the best at the other extreme.  We use NOTHING except Eager Thick at all.  Performance testing has proven over and over that is is the best.
One point I would like to add on is to check with your SAN vendor to see what they recommend since some / most SAN vendor have API's that hook into Vmware via the VAAI
Neil RussellTechnical Development Lead

Commented:
And some also recommend disable VAAI as it causes worse performance in SOME configurations.

As always there is NO 100% correct answer.
What type of SAN or shared storage  device are you using???

Author

Commented:
Hello Experts,

Thanks for you're response, however I don't think any expert has actually answered my question...
"Batchelor", Developer and EE Topic Advisor
Top Expert 2015
Commented:
In short: Thin provisoning has worst performance. Eager Thick has best.

Thin will only allocate the used space physically. This requires the allocated space to grow dynamically, which causes more overhead. But it allows to have a lot of virtual disk space (more than physically is available in total for all Thin Provisioned VMs).

Thick allocates the whole configured space on creation. It then depends on Eager or Lazy:
Eager Zero writes zeroes to the complete allocated space on creation. Storage systems will definitely allocate physical disk space, and writing to those will not add any overhead.
Lazy Zero writes zeroes only when writing blocks. Storage systems using a virtual allocation scheme might allocate physical space now. But that might introduce some overhead, causing delays.

In regard of using already allocated space, there should be no difference in performance, though Thin might have a slightly worse performance because of the added administrative overhead for "fragmentation" treatment.

Author

Commented:
Qlemo,

That's exactly the answer a novice like me needed.

Thanks

Author

Commented:
Cheers