Hi Salem, we are not using VAAI in our environment, thank you for doc links.  Rohang, yes whatever vm admins provisioned of type eagarzerothick , they are performance critical and won't take hit of any perf related issues to we can rule out of using zeropagereclaim on those LUNs.  Lazyzeroedthick and thin devices: "Running a zero space reclaim for Lazyzeroedthick and thin devices will definitely help because it will reclaim areas that have been written by host and subsequently zeroed. For example, you delete files on the disk and you want the guest OS to reuse that space, which will otherwise remain unused."  As per vmware doc ( here i attach the specific page ) if we delete files/vmdks on the lazyzerothink/thin disks the space won't come back until the vmware team runs the unmap/vmfsktools. correct me if i am wrong.
hello,  As we have 3 provision types in vmware  Eagerzeroedthick:  In this format, the size of the VDMK file on the datastore is the size of the virtual disk that you create, and within the file, it is “pre-zeroed”.  Lazyzerothick: In this format, the size of the VDMK file on the datastore is the size of the virtual disk that you create, but within the file, it is not “pre zeroed”.  Thin: In this format, the size of the VDMK file on the datastore is only how much is used within the VM itself.  Bascially from attached screen shot, if we run zeropagereclaim ( full volume ) of Eagerzerothick volume on storage array it reclaim all portions of virtual disk that contain continuous zero, so if i run this basically it nullifying the benefit of eagerzerothick devices ( which are created by vmteam for prod/critical servers ).  and it won't works on Lazyzerothick and thin devices ( because guest os  won't write zeros ) so question is whats the point of running zeropagereclaim on storage array ?
Zeropagereclaim - VMware provision