topic Thin FlexClone Lun from Thick in ONTAP Discussions

Thin FlexClone Lun from Thick

ALEX_BARANOV — Thu, 05 Jun 2025 05:22:32 GMT

Hello.

I have unusual behavior of function clone-start (Creating Flex clone) on 7-Mode.
I have a thick Volume and thick Lun on it. I try to create FlexClone Lun with parameter space-reserve:false (i.e. clone will be thin provisioned) and use temporary snapshot (without existing snapshot). If the lun has used space more than available space on the volume, function has failed with error: "Clone operation failed to start: Volume is full or Volume crossed autodelete threshold..".
For example:
   Volume: 1GB (Available: 300MB), Lun: 700MB (Used: 650MB) - FlexClone doesn't work
   Volume: 1GB (Available: 300MB), Lun: 700MB (Used: 100MB) - FlexClone works

But, If I do this operation and select existing snapshot, it works. Traditional lun clone works too.

What does it mean, what am I doing wrong?

Re: Thin FlexClone Lun from Thick

deepuj — Wed, 17 Dec 2014 05:28:23 GMT

Hi,

Flex clones will not use any additional space, space is required only for the data you write to flex clone.

Check how many snapshots are there for the volume, is auto delete of snapshots enabled?

Try to create a flex clone with out a snapshot copy creation using -n option

Thanks

Re: Thin FlexClone Lun from Thick

ALEX_BARANOV — Wed, 17 Dec 2014 10:28:25 GMT

Volume doesn't have a snapshot.

AutoDel snapshot on volume is disabled.

Flexclone

al-na-821-7m> clone start /vol/mike_vol/mike_lun /vol/mike_vol/mike_lun_clone -o  
clone start: Volume is full or Volume crossed autodelete threshold

But Flexclone from snapshot works.

al-na-821-7m> clone start /vol/mike_vol/mike_lun /vol/mike_vol/mike_lun_clone -s snapshot_17 -o                                                                     Clone operation started successfully. ID: 9.

Re: Thin FlexClone Lun from Thick

deepuj — Wed, 17 Dec 2014 11:10:45 GMT

Can you try "-n" instead of "-o"?

Re: Thin FlexClone Lun from Thick

ALEX_BARANOV — Wed, 17 Dec 2014 11:52:31 GMT

But it shouldn't work without option "-o" in my case, when source Lun uses space reservation

-o : Skip space reservation on the clone when cloning entire file/LUN.
-n : Do not use temporary snapshot for cloning. (Deprecated.)

I have tried.

al-na-821-7m> clone start /vol/mike_vol/mike_lun /vol/mike_vol/mike_lun_clone -n
clone start: Volume is full or Volume crossed autodelete threshold..

al-na-821-7m> clone start /vol/mike_vol/mike_lun /vol/mike_vol/mike_lun_clone1 -n -s snapshot_17
clone start: Volume is full or Volume crossed autodelete threshold..