Dear Data Storage Experts,
We are using a SAN attached thin-provisioned LUN on Physical Windows machine from a storage vendor. Storage chargeback is based on high watermark (deleted space not reclaimed properly).
Consider following scenario:
- 500GB LUN attached to Windows as F:
- Case 1) We fill the F: drive to 99% with data, Vendor storage portal will say ~500GB used and we get charged for 500GB.
- Case 2) We delete all of the data on F:, Vendor storage portal will still say ~500GB used(high watermark) and get chargeback for 500GB.
Heard that writing zeros to the deleted space will actually reclaim the space for thin provisioned device. I tried using sdelete, cipher, fsutil to confirm the binary zeros are written to the deleted space. Vendor portal is still showing ~500GB used. Followed this link but no luck.
Really appreciate any help on this.
Edit 1 : SCSI_UNMAP looks interesting. Changing
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem\DisableDeleteNotification to 1 might solve this issue but can be performance heavy. Checking such options now, thanks again for reading my post.