If your Zimbra server's storage is running out or you try to keep your virtual machines lean and easily transferrable it might be necessary to put Zimbra's mail storage on a different file system or storage medium.

The process is straightforward; they key is knowing that Zimbra stores mail in /opt/zimbra/store.

In my case, I'm creating and attaching a 20 GB sparse file to a virtual machine:

# dd if=/dev/zero of=storage.img seek=20000 bs=1M count=0
# mke2fs -j storage.img

After attaching your storage and creating the file system boot your Zimbra server (if necessary) and mount the file system to /mnt/tmp

# mkdir /mnt/tmp
# mount /dev/sda2 /mnt/tmp

Shut down Zimbra if it is running.

# /etc/inid.d/zimbra stop

Change the ownership of the new file system's root directory to your zimbra user:

# chown zimbra: /mnt/tmp

Move the contents of /opt/zimbra/store (or wherever your store directory is located) to /mnt/tmp:

# mv /opt/zimbra/store/* /mnt/tmp/

Unmount /mnt/tmp:

# umount /mnt/tmp

Now create an appropriate fstab entry for /opt/zimbra/store using the new file system's device node/label/etc.:

/dev/sdb1       /opt/zimbra/store       ext3    defaults,noatime        0 0

Mount /opt/zimbra/store and start Zimbra:

# mount /opt/zimbra/store
# /etc/init.d/zimbra start