UPDATE: 3par InForm OS 2.3.1 supports Zero detection and can reclaim the 0′s to keep disks thin. This is done by a special ASIC therefore keeping performance impact at near nothing.

I have never visibly seen too bad of a performance hit using just zerothick. I always would rather plan ahead to avoid follow up calls ( I do professional service installs) related to slowness.

Another note: It will be slow to deploy a big eagerzeroedthick disk if it is very big.

I agree that eagerzerothick is great for high I/O VMs, it should be carefully considered as systems that Thin Provision like NFS or V-Max (and many others) will allocate all space once the vmdk is eagerzero.

zerothick continues to play nice with these technologies, but you do pay some I/O penalty for the thin provisioning which continues to be less and less with each VMFS revision.

In our testing, we saw marginal benefits (1-4% performance) from eagerzero over zero running SQL loads. We do have a very large EMC V-Max SAN however to cover some of this I/O. We now only use eagerzero for MSCS VMs.

Good post, and small option many people miss or just overlook!

Great suggestion. Your link to the white paper isn’t working. I’d be interested to read the reasoning behind the FT performance increase for high IO VMs.