Just wondering what people have to say about Thin provisioned VMDK hard disks on NFS datastores, specifically is holepunching or some other similar function good to do after zeroing out free space in a VM?
eg after running a SDelete -z to zero out free space
I previously wasn't using compression due to the older version of OmniOS / ZFS being slower than I liked with it turned on.
When doing some benchmarking it doesn't seem to affect things much on the newer version of omnios-r151028 and ESXi 6.5..
Compression OFF
Compression ON (LZ4)
After some searching around I realized that holepunching isn't actually a supported on NFS mounted VMDKs:
However, while testing out compression again I noticed that the space was automatically re-claimed on test VMDKs stored on compression=lz4 datasets shared over NFS to ESXi 6.5:
Does this mean that you don't need to do anything else besides zeroing out free space after deleting large files from within the VM if you find your thin-provisioned VMDKs getting much larger than the "real" filesystem contents within the VM?
Thanks!
eg after running a SDelete -z to zero out free space
I previously wasn't using compression due to the older version of OmniOS / ZFS being slower than I liked with it turned on.
When doing some benchmarking it doesn't seem to affect things much on the newer version of omnios-r151028 and ESXi 6.5..
Compression OFF
Compression ON (LZ4)
After some searching around I realized that holepunching isn't actually a supported on NFS mounted VMDKs:
Code:
# vmkfstools --punchzero bak01_1.vmdk
Not a supported filesystem type
However, while testing out compression again I noticed that the space was automatically re-claimed on test VMDKs stored on compression=lz4 datasets shared over NFS to ESXi 6.5:
Code:
root@vsan2:/# ls -alh /vm2/test/bak01/
total 2276725
drwxr-xr-x 2 root root 5 Mar 20 17:22 .
drwxr-xr-x 3 root root 3 Mar 20 17:22 ..
-rwxrwxr-x 1 root root 84 Mar 20 17:23 .lck-bf00000000000000
-rw------- 1 root root 40G Mar 20 17:23 bak01_1-flat.vmdk
-rw------- 1 root root 499 Mar 20 17:22 bak01_1.vmdk
root@vsan2:/vm2/test/bak01# du -ah
778M ./bak01_1-flat.vmdk
4.50K ./bak01_1.vmdk
512 ./.lck-2400000000000000
778M .
root@vsan2:/vm2/test/bak01# echo SDelete_-z
SDelete_-z
root@vsan2:/vm2/test/bak01# du -ah
16.7M ./bak01_1-flat.vmdk
4.50K ./bak01_1.vmdk
512 ./.lck-2400000000000000
16.7M .
Thanks!