topic Re: Autosize on a Snapmirror Destination Volume in ONTAP Discussions

Autosize on a Snapmirror Destination Volume

christop — Thu, 05 Jun 2025 07:15:41 GMT

Hi:

Are there any gotchas with using autosize on a snapmirror destination? I understand that the destination is not aware if the source has been autosized, but would a destination vol autosize itself even while it is restricted during a transfer? Would it be better to just grow the destination to a value close to the size of the aggregate?

Thanks,

Chris

Re: Autosize on a Snapmirror Destination Volume

amiller_1 — Sun, 18 Apr 2010 04:50:45 GMT

Hmmm.....I'm thinking this would only apply to QSM as VSM requires the destination volume to be restricted (there's some well-documented manual steps to expand a VSM destination volume).

For a QSM relationship, I don't see how there would be any problem with autosize.

Re: Autosize on a Snapmirror Destination Volume

alapati — Mon, 19 Apr 2010 14:39:19 GMT

autosize on VSM destination does not work in snapmirrored state. It is available after break and after turning off fs_size_fixed option.

Re: Autosize on a Snapmirror Destination Volume

adaikkap — Mon, 19 Apr 2010 17:24:26 GMT

Snapmirror destination will always be the exact replica of the source, vol options like autogrow, snap auto delete, vol guarantee etc.

So even if autosize is turned on in the destination, on snapmirroring it will follow the source(autosize is off on source), only on mirror break the autosize will be turned on.

But since fs_size_fixed set to ON in the destination even on mirror break, autosize cant take effect.

so you will have to turn fs_size_fixed to off , so autosize can take effect.

A better way would be to create a none guaranteed volume with 2x size than your source so the volume doesn't consume any space from the aggr.

On snapmirroring the destination volume size will the exact size of the source volume and only that much space would be consumed from the aggr.

Even if the source grows since the snapmirror destinatoin volume actual size is 2x the source it will grow till that size, with out snapmirror failing.

Even better would be to create aggr sized volume of none guarantee.

Regards

adai