5.4. Moving swap File Systems from a Single Path Device to a Multipath Device
By default, swap devices are set up as logical volumes. This does not require any special procedure for configuring them as multipath devices as long as you set up multipathing on the physical volumes that constitute the logical volume group. If your swap device is not an LVM volume, however, and it is mounted by device name, you may need to edit the
fstab
file to switch to the appropriate multipath device name.
- Determine the WWID number of the swap device by running the
/sbin/multipath
command with the-v3
option. The output from the command should show the swap device in the paths list.You should look in the command output for a line of the following format, showing the swap device:Copy to Clipboard Copied! Toggle word wrap Toggle overflow WWID H:B:T:L devname MAJOR:MINOR
WWID H:B:T:L devname MAJOR:MINOR
For example, if your swap file system is set up onsda
or one of its partitions, you would see a line in the output such as the following:Copy to Clipboard Copied! Toggle word wrap Toggle overflow ===== paths list ===== ... 1ATA WDC WD800JD-75MSA3 WD-WMAM9F 1:0:0:0 sda 8:0 ...
===== paths list ===== ... 1ATA WDC WD800JD-75MSA3 WD-WMAM9F 1:0:0:0 sda 8:0 ...
- Set up an alias for the swap device in the
/etc/multipath.conf
file:Copy to Clipboard Copied! Toggle word wrap Toggle overflow multipaths { multipath { wwid WWID_of_swap_device alias swapdev } }
multipaths { multipath { wwid WWID_of_swap_device alias swapdev } }
- Edit the
/etc/fstab
and replace the old device path to the root device with the multipath device.For example, if you had the following entry in the/etc/fstab
file:Copy to Clipboard Copied! Toggle word wrap Toggle overflow /dev/sda2 swap swap defaults 0 0
/dev/sda2 swap swap defaults 0 0
You would change the entry to the following:Copy to Clipboard Copied! Toggle word wrap Toggle overflow /dev/mapper/swapdev swap swap defaults 0 0
/dev/mapper/swapdev swap swap defaults 0 0