topic Re: How to reduce the size of snapmirror volume from destination in ONTAP Discussions

How to reduce the size of snapmirror volume from destination

RIMSTORAGE — Thu, 05 Jun 2025 05:27:23 GMT

Hi Everyone ,

I have some queries regarding resizing the snapmirror volume . Below is the details.

I have one volume suppose name of volume is volume A , which is getting replicated from filer A to filer B and then from filer B to filer C. Volume size is 3TB and it is same on all the filers.

Recently i have reduced the size of volume A on filer A and make it 2.5 TB, so now what is the procedure to reduce the size of volume on filer B and filer C so that we can reclaim the unused space.

Any suggestion is highly appreciated.

Thanks in advance.

Re: How to reduce the size of snapmirror volume from destination

JGPSHNTAP — Mon, 13 Oct 2014 13:51:17 GMT

If its your DR copy, in my opinion it should be thin provisioned to begin with.

But if you are thick provisioned, just run vol size commands

Re: How to reduce the size of snapmirror volume from destination

nicholaf — Mon, 13 Oct 2014 14:02:23 GMT

You want the destination volume to be no smaller than the source. With that in mind you can reduce the size of the destination by turning off the fs_size_fixed option on the destination. When you create a snapmirror relation this option in automatically enabled on the destination. To see what I mean type vol options [volname]. To disable fs_size_fixed type 'vol options [volname] fs_size_fixed off. Then you can use the vol size command to change the volume size of the destination. Once complete re-enable the fs_size_fixed option & check your snapmirror relationship with the 'snapmirror status' command. If you want to test your snapmirror relationship before it's scheduled you can use the snapmirror update command.

Regards,

Nicholas Lee Fagan

Re: How to reduce the size of snapmirror volume from destination

RIMSTORAGE — Mon, 13 Oct 2014 14:51:54 GMT

Hi NICHOLAF,

Thanks a lot for your reply. I understand that we need to change the option fs_size_fixed to off. But i am also come to know that snapmirror destination volume is always in read only mode. So making the option fs_size_fixed to off is enough? Will it allow me to resize while in read only mode or i need to do some more chnages before resizing the volume.

Do you have any document related to this , if any kindly share.

Thanks a lot...............

Re: How to reduce the size of snapmirror volume from destination

JGPSHNTAP — Mon, 13 Oct 2014 15:01:56 GMT

This isn't that difficult.. Just do vol options to change fixed size to off and you can just resize the DR Side

vol size volume (newsize)

If you just found out that netapp snapmirror side is read-only, perhaps you can review some of the WBT to get yourself more familiar with this

Re: How to reduce the size of snapmirror volume from destination

aborzenkov — Mon, 13 Oct 2014 15:13:38 GMT

Fs_size_fixed is filesystem size, not volume size, and is changed automatically to match source next time SnapMirror update completes. After that volume size can be reduced to match filesystem size.

Re: How to reduce the size of snapmirror volume from destination

nicholaf — Mon, 13 Oct 2014 17:54:51 GMT

Yes, that will be enough. If more is necessary to resize the volume the system will be sure to let you know (ie. try the vol resize command while fs_fixed_size in enabled, the system will notify you to turn it off). You can remove the read-only option too if you'd like though but it should be re-enabled before the snapmirror transfer begins. You can change the volume from read-only to full permissions with the vol restrict command.

Regards,

Nicholas Lee Fagan

Re: How to reduce the size of snapmirror volume from destination

RIMSTORAGE — Tue, 14 Oct 2014 08:55:30 GMT

Thanks everyone for your support , i will implement it and will let you know the status.

Beside this i have one more query , i am having one volume in my filer so is there a way to find what are the hosts mouting that volume ( i have exported that volume to everyone) so i am not sure about the hosts using that volume . Now i want to know what are the hosts using that volume.

I am using the command nfsstat -l to see the NFS statistics , but it is not showing specific to volume . It is giving me the lists of hosts only which are hitting my filer through NFS .

Thanks a lot in advance......................

Re: How to reduce the size of snapmirror volume from destination

RIMSTORAGE — Tue, 14 Oct 2014 15:56:16 GMT

Hi Everyone,

We are able to reduce the size of the volume just running the single command "vol size <vol name> -n".

Thanks a lot for your suggestions.