Extending mdadm RAID and LVM
This article details the process of extending your mdadm raid and LVM
Already preconfigured mdadm raid on a 45 Drives unit
Extending an mdadm RAID and then growing your LVM can be done in a few simple steps, but you’ll need to set aside some time to allow the RAID to re-sync.
Below are the steps that were taken to grow a 6 drive RAID6 with XFS, to a 9 drive RAID6 and then growing our LVM from 100Gb to 1000Gb.
1. Add 3 more drives to the RAID
mdadm --add /dev/md0 /dev/sd[ghi]' (where /dev/md0 is the RAID, and /dev/sd[ghi] are the 3 drives being added) mdadm --grow --raid-devices=9 /dev/md0 *This process was rather slow (~500-600 minutes)
2. Resize the Physical Volume
3. Resize the Logical Volume
lvextend -L +X /dev/lvm/root (where X is the amount of space to be added, and /dev/lvm/root is the location of the Logical Volume)
4. Mount the volume
mount -t xfs /dev/lvm/root /Volume (where /Volume is the mount point for our logical volume)
5. Extend the filesystem to include the added space
xfs growfs /Volume
6. Check to see that the mounted volume is now updated
df -h * This should result in showing your volume mounted at your chosen mount point with the additional space added.