Maintain SAN volumes

You can use the Xsan pane of the Server app to change the name of a volume. You can’t rename an Xsan volume using the Finder.

1. In the Xsan pane of the Server app, select the volume you want to rename.

2. Click the Action pop-up menu , then choose Edit Volume.

3. Select the volume name, then edit it.

4. Click OK.

You can destroy a volume, and reuse its LUNs to create new volumes.

• In the Xsan pane of the Server app, select the volume in the list, then click Remove .

When you create a file, Xsan divides the file into pieces and distributes these pieces efficiently over the LUNs that make up one of the volume’s storage pools. Over time, as the file is modified, its pieces become fragmented in less efficient arrangements.

You can use the snfsdefrag command-line tool to check the amount of file fragmentation, or use the cvfsck command-line tool to check the amount of free space fragmentation.

• Open Terminal (in the /Applications/Utilities/ folder) on any SAN computer.

  If you aren’t working at a SAN computer, use SSH to log in to a SAN computer remotely:

  $ ssh user@computer

  Replace user with the name of an administrator user on the SAN computer and computer with the SAN computer’s name or IP address.

  If you have trouble making an SSH connection, check the Sharing pane of System Preferences on the SAN computer to make sure Remote Login service is turned on.

  For more information, see the cvfsck or snfsdefrag man page.

You can use the snfsdefrag command-line tool to defragment a file, a folder, or an entire volume.

Defragmenting a file reassembles its pieces into the most efficient arrangement.

1. Open Terminal (in the /Applications/Utilities/ folder) on any SAN computer.

   If you aren’t working at a SAN computer, use SSH to log in to a SAN computer remotely:

   $ ssh user@computer

   Replace user with the name of an administrator user on the SAN computer and computer with the SAN computer’s name or IP address.

   If you have trouble making an SSH connection, check the Sharing pane of System Preferences on the SAN computer to make sure Remote Login service is turned on.

   For more information, see the snsfdefrag man page.

2. Run the snfsdefrag command-line tool.

   To defragment individual files:

   $ sudo snfsdefrag -v filename [filename... ]

   To defragment a folder:

   $ sudo snfsdefrag -vr folder

   To defragment a volume, set folder to the volume name.

If SAN users have trouble accessing files, use the cvfsck command-line tool to check the integrity of a volume, its metadata, and its files.

1. Open Terminal (in the /Applications/Utilities/ folder) on any SAN computer.

   If you aren’t working at a SAN computer, use SSH to log in to a SAN computer remotely:

   $ ssh user@computer

   Replace user with the name of an administrator user on the SAN computer and computer with the SAN computer’s name or IP address.

   If you have trouble making an SSH connection, check the Sharing pane of System Preferences on the SAN computer to make sure Remote Login service is turned on.

2. Run the cvfsck command-line tool (in /System/Library/Filesystems/acfs.fs/Contents/bin/) to check the volume without making repairs:

   $ sudo cvfsck -vn volume

You’ll see a warning that the journal is active; this is normal.

For more information, see the cvfsck man page.

If the cvfsck tool reveals problems with a volume, you can use the cvfsck command-line tool to repair the volume.

1. Stop the volume.

   Open the Xsan pane of the Server app, select the volume, and click Stop Volume in the Action pop-up menu . The volume will be unmounted on all SAN computers.

2. Open Terminal (in the /Applications/Utilities/ folder) on any SAN computer.

   If you aren’t working at a SAN computer, use SSH to log in to a SAN computer remotely:

   $ ssh user@computer

   Replace user with the name of an administrator user on the SAN computer and computer with the SAN computer’s name or IP address.

   If you have trouble making an SSH connection, check the Sharing pane of System Preferences on the SAN computer to make sure Remote Login service is turned on.

   For more information, see the cvfsck man page.

3. Run the cvfsck command-line tool (in /System/Library/Filesystems/acfs.fs/Contents/bin/) to replay the events that are recorded in the file system journal:

   $ sudo cvfsck -j volume

4. Check the volume to see if repairs are required:

   $ sudo cvfsck -vn volume

5. If the report generated in the previous step lists problems, enter the following command to perform a full check and repair of the volume:

   $ sudo cvfsck -vw volume

6. Take the volume online.

   In the Xsan pane of the Server app, select the volume, and click Take Volume Online in the Action pop-up menu .