Using LUN clones

What a LUN clone is

A LUN clone is a copy of a writable snapshot of a LUN. After the clone process is completed, the LUN resides entirely in the active file system and does not depend on any snapshots.

What LUN clones are used for

You can use LUN clones to create a permanent copy of the LUN at the time the snapshot of the original LUN was taken. You can use it when you need to delete a snapshot of a LUN without taking the LUN offline or losing its contents. You can clone the contents of the writable snapshot of the LUN without any disruption to an application using the LUN. After the clone operation is complete, you can delete the snapshot.

Note
Cloning is not NVLOG protected, so if the filer panics during a clone operation, the operation is restarted from the beginning on a reboot or takeover.

Creating a writable snapshot of a LUN

Before you can clone a LUN, you must create a writable snapshot of the LUN you want to clone. To create a writable snapshot, complete the following steps.

Step	Action
1	Create a LUN by entering the following command: lun create -s size lun_path Example `lun create -s 100g /vol/vol1/lun0`
2	Create a snapshot of the volume containing the LUN to be cloned by entering the following command: snap create volume_name snapshot_name Example `snap create vol1 mysnap`
3	Create a writable LUN by entering the following command: lun create -b snapshot_lunpathname lun_clone_path Example `lun create -b /vol/vol1/.snapshot/mysnap/lun0 /vol/vol1/snaplun0`

Step

Action

Create a LUN by entering the following command:

lun create -s size lun_path

Example

lun create -s 100g /vol/vol1/lun0

Create a snapshot of the volume containing the LUN to be cloned by entering the following command:

snap create volume_name snapshot_name

Example

snap create vol1 mysnap

Create a writable LUN by entering the following command:

lun create -b snapshot_lunpathname lun_clone_path

Example

lun create -b /vol/vol1/.snapshot/mysnap/lun0 /vol/vol1/snaplun0

Starting the cloning process

To clone a LUN, complete the following step.

Step	Action
1	Begin the clone operation by entering the following command: lun clone start lun_clone_path

Displaying the progress of the clone operation

To display the progress of the clone operation, complete the following step.

Step	Action
1	Enter the following command: lun clone show lun_clone_path

Stopping the cloning process

If you need to stop the clone process, complete the following step.

Step	Action
1	Enter the following the command: lun clone stop lunpath