topic Re: Down sizing flexvol containing LUNS in ONTAP Discussions

Down sizing flexvol containing LUNS

mn1970 — Wed, 04 Jun 2025 13:49:56 GMT

Just a quick question to double check.. we have a number of flexvols ( thick ) that contain thin provisioned LUNs, now that the LUNs are populated and dedupe etc has done its work the LUNs take up barely a quarter of the flexvols. I presume its safe to shrink the size of the flexvols on the fly to a more realistic size without having impact on the LUNs.

Re: Down sizing flexvol containing LUNS

GidonMarcus — Tue, 10 Apr 2018 16:08:25 GMT

Shrinking the volume should be ok and not impact your LUN as long you leaving enough space for snapshot reserve ( vol show -fields percent-snapshot-space), if you exceed this, the LUN will go offline.

and of-course also putting here another warning (less directed for you - but more to whoever find this in google in a year time) never shrink the LUN itself without a dedicated tool that can adjust on OS file system layout (for example snap drive)

gidi

Re: Down sizing flexvol containing LUNS

mn1970 — Wed, 11 Apr 2018 08:56:56 GMT

Thanks, the flexvol is set to grow and delete older snapshots should space become an issue.

Re: Down sizing flexvol containing LUNS

GidonMarcus — Wed, 11 Apr 2018 09:49:51 GMT

that wasen't the point. what i was pointing to is that the situation below will not be allowed. and the LUN will go offline as soon as it hit the snap reserve space even if there's snapshots that available to be deleted. . as it name suggest - it pre-reserved for -ONLY- snapshot use and cannot be used by the actual LUN.