1

How to convert linux SWAP memory from RAID1 to RAID0?

Start with:
2 exact size swap formatted partitions (/dev/sdc5 and /dev/sdd5) on 2 physically separate disks that are used via Software RAID
(named md127, located /dev/md/s) in RAID 1 (Mirroring)

cat /proc/mdstat

would show for md127 something like:

md127 : active raid1 sdc5[2] sdd5[0]
      7806976 blocks super 1.2 [2/2] [UU]

The task is to use the same:
2 exact size swap formatted partitions (/dev/sdc5 and /dev/sdd5) on 2 physically separate disks that are used via Software RAID
(named md127, located /dev/md/s) in RAID 0 (Striping)

cat /proc/mdstat

would show for md127 something like:

md127 : active raid0 sdc5[2] sdd5[0]
      15613952 blocks super 1.2 64k chunks

Convert SWAP /dev/md/s from RAID1 to RAID0 with mdadm

For this you need to know:

  • the difference between RAID0 and RAID1
  • when the Operating System uses SWAP partition (for ex: when you are about to run out of free available physical memory)
  • how to monitor the memory usage (via a tool like conky)
1

Please find below a simple way to achieve the requested.
I did not really need help. Mostly sharing to whoever it might help.

To start you may want to check the details of /dev/md/s

sudo mdadm --detail /dev/md/s

Then "grow" the RAID to RAID0.
This will loose one partition, but that's ok with us:

sudo mdadm /dev/md/s --grow --level=0

Then add the missing partition back using the command below. This will temporary change to a RAID4 and convert to RAID0 when completed

sudo mdadm --grow /dev/md/s --raid-devices=2 --add /dev/sdc5

To check progress you could use:

cat /proc/mdstat

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.