Stabilizing (quiescing) destinations before taking a snapshot

Why to block data transfers to a destination temporarily

You may need to temporarily stop transfers to a destination. For example, if you want to create a snapshot of a SnapMirror destination volume or qtree that contains a database, you may need to ensure that its contents are stable during the snapshot. You can use the snapmirror quiesce command to block transfers to the destination after the destination reaches a stable state.

What the quiesce command does

The snapmirror quiesce command waits for all existing transfers to both volumes and qtrees to complete and blocks any further updates. If a qtree is not in a stable state (is in transition), the snapmirror quiesce command forces it into a stable state.

You can quiesce only volumes and qtrees that are online and that are SnapMirror destinations.You cannot quiesce a restricted or offline volume or a qtree in a restricted or offline volume.

The snapmirror quiesce command stops a volume or qtree from acting as a SnapMirror destination, but does not prevent it from acting as a SnapMirror source.

Note
The quiesced state persists across reboots.

How to quiesce data transfers

To stabilize and halt updates to data on a SnapMirror destination volume or qtree, complete the following step.

Step	Action
1	Enter the following command on the filer on which you want to block transfers: *snapmirror quiesce {dest_volume* \| /vol/volume_name/qtree_name}** dest_volume is the name of the destination volume. qtree_name is the name of a qtree in volume_name.

Example 1

filerA> snapmirror quiesce vol1

snapmirror quiesce: in progress.

snapmirror quiesce: vol1: successfully quiesced

Result

SnapMirror stops any further data transfers to vol1.

Example 2

filerA> snapmirror quiesce vol2

snapmirror quiesce: in progress.

This can be a long-running operation. Use Control-C to interrupt.

......................................

snapmirror quiesce: vol2: successfully quiesced

Result

SnapMirror waits for a transfer to finish and stops any further data transfers to vol2.

Example 3

filerA> snapmirror quiesce /vol/vol1/qtree1

Result

SnapMirror stops data transfers to qtree1 in vol1.

If you use the snapmirror break command on a destination that is quiesced, the quiesce condition is automatically cleared when the destination becomes writable.

Resuming transfers after quiescing a destination

You can use the snapmirror resume command to restore the capability for data transfer to a volume or qtree you have quiesced.

To resume SnapMirror transfers, complete the following step.

Step	Action
1	Enter the following command for the filer on which you want to resume transfers: *snapmirror resume {dest_volume* \| /vol/volume_name/qtree_name}** dest_volume is the name of the destination volume. qtree_name is the name of a qtree in volume_name. Example filerA> snapmirror resume vol2 snapmirror resume: vol2: Successfully resumed Result SnapMirror resumes normal data transfer capability for vol2.

Step

Action

Enter the following command for the filer on which you want to resume transfers:

snapmirror resume {dest_volume | 
/vol/volume_name/qtree_name}

dest_volume is the name of the destination volume.

qtree_name is the name of a qtree in volume_name.

Example

filerA> snapmirror resume vol2

snapmirror resume: vol2: Successfully resumed

Result

SnapMirror resumes normal data transfer capability for vol2.