Converting a destination to a writable volume or qtree

Why to convert a destination to a writable volume

You can use the snapmirror break command to convert a SnapMirror destination, with read-only status, to a writable volume or qtree. You might want to convert a destination to a writable volume or qtree to perform one of the following tasks:

Data migration--You want to move your user's working data from one volume or qtree (your current source volume or qtree) to another volume or qtree (your current destination volume or qtree) and make that data accessible and writable in its new location.
Disaster recovery--In case your source volume or qtree is suddenly unavailable, you want your current destination volume or qtree to serve as the substitute for your users' retrieval and input source.
Application testing--You want to make your current destination volume or qtree writable to test a new application on a mirrored replication of your current data rather than risk corruption of original data on the source volume or qtree.

Converting the destination to a writable volume or qtree lets you use data on the destination for these situations or in any other situation in which the original source is unavailable.

Preserving quota restrictions

Quotas are always disabled on a SnapMirror volume destination, regardless of whether quotas are enabled on the source volume. If you try to enable quotas on a volume destination, SnapMirror displays an error message. Quotas are not disabled on SnapMirror destination qtrees.

If the source volume or qtree and the destination reside on different filers, and you want the same quota restrictions to be applied after you make the destination writable, the destination filer must have an /etc/quotas file that includes all the entries from the /etc/quotas file used by the source filer.

If you use SnapMirror replication for data migration, you can copy the /etc/quotas entries from the source filer to the /etc/quotas file of the destination filer before you use the snapmirror break command to make the destination writable.
If you use SnapMirror replication for backup and potential disaster recovery, you must keep a copy on the destination filer of all /etc/quotas entries used by the source filer at all times. That way, you can apply the quota entries to the destination volume or qtree if the source filer becomes unavailable.

Converting to a writable volume or qtree

To convert a destination to a writable volume or qtree, complete the following steps.

Step	Action
1	On the destination filer use the `snapmirror break` command to make the destination volume or qtree writable. To make a destination volume writable, enter the following command on the destination filer. snapmirror break volume_name To make a destination qtree writable, enter the following commands on the destination filer. snapmirror quiesce /vol/volume_name/qtree_name snapmirror break /vol/volume_name/qtree_name
2	If you want to enable quotas on the former destination volume, carry out the following steps. Edit the /etc/quotas file on the former destination filer so that, after the conversion, the former destination includes the same quota restrictions as the source volume. If the original source volume uses per-volume quotas, replace the original source volume name with the former destination name in the quota entries. Enter the following command to enable quotas on the former destination: quota on volume_name
3	Consider the following optional measures: If you want to stop a SnapMirror source from trying to update a broken-off destination, you can delete or comment out the entry in the /etc/snapmirror. conf file. Otherwise SnapMirror continues to try to update the destination. You might also want to use the `options fs_size_fixed off` command to turn off the option that restricts the size of the file system on a destination volume. Note However, after you set `options fs_size_fixed off,` the ability of the destination and source volumes to resync is not guaranteed. For more information, see How snapmirror initialize matches source and destination volume size.

Step

Action

On the destination filer use the snapmirror break command to make the destination volume or qtree writable.

To make a destination volume writable, enter the following command on the destination filer.
```
snapmirror break volume_name
```

To make a destination qtree writable, enter the following commands on the destination filer.

snapmirror quiesce /vol/volume_name/qtree_name

snapmirror break /vol/volume_name/qtree_name

If you want to enable quotas on the former destination volume, carry out the following steps.

Edit the /etc/quotas file on the former destination filer so that, after the conversion, the former destination includes the same quota restrictions as the source volume.
If the original source volume uses per-volume quotas, replace the original source volume name with the former destination name in the quota entries.
Enter the following command to enable quotas on the former destination:
```
quota on volume_name
```

Consider the following optional measures:

If you want to stop a SnapMirror source from trying to update a broken-off destination, you can delete or comment out the entry in the /etc/snapmirror. conf file. Otherwise SnapMirror continues to try to update the destination.
You might also want to use the options fs_size_fixed off command to turn off the option that restricts the size of the file system on a destination volume.
Note
However, after you set options fs_size_fixed off, the ability of the destination and source volumes to resync is not guaranteed.

For more information, see How snapmirror initialize matches source and destination volume size.

After using snapmirror break

After using the snapmirror break command to temporarily break a SnapMirror relationship between a source and destination, you can use other SnapMirror commands to either make the break permanent or restore or redefine the SnapMirror relationship.

Use the snapmirror release command to make the break permanent. See Releasing partners from a SnapMirror relationship.
Use the snapmirror resync command to restore or redefine the SnapMirror relationship. See Resynchronizing SnapMirror.