topic Thin Provisioned LUN space usage in Data Protection

Thin Provisioned LUN space usage

christop — Thu, 05 Jun 2025 06:31:13 GMT

I want to confirm I have the expected behavior of LUN usage from a host perspective in a thin provisioned environment.

Assumptions:

- LUN is thin provisioned with no fractional reserve, no volume guarantees

- No snapshots present

My lun used on the storage system will continue to grow until it reaches 100%. The host side will see usage based on filesystem usage (i.e. when a file is deleted space will become available).

The storage system lun usage will go down if a space reclamation tool - such as SnapDrive - is enabled, otherwise the lun usage will stay at 100%.

Is this correct?

Re: Thin Provisioned LUN space usage

scottgelb — Tue, 27 Mar 2012 18:44:42 GMT

Correct.. the host will see the full size of the lun. The netapp controller will take space only as data is written, but like you said without space reclamation, host deletes won't delete on the netapp without snapdrive reclamation. If you have room for the full lun size though you are ok since you are not running snapshots and won't overrun more than the lun size itself.

Re: Thin Provisioned LUN space usage

christop — Tue, 27 Mar 2012 18:57:02 GMT

Great - thanks Scott!