raid howto is located in Crypto
https://raid.wiki.kernel.org/index.php/RAID_Recovery
if a raid is degraded, save superblock infos first:
mdadm --examine /dev/sd[abcd]1 > /etc/_raid/mdadm--examine_2013-03-10
check, whats up:
mdadm --detail /dev/md1
re-add a removed device:
mdadm /dev/md1 --add /dev/sda2
watch revovery:
watch cat /proc/mdstat
update existing initramfs:
update-initramfs -u -k all
update the raid config - achtung “»” adds to the files, “>” overwrites:
mdadm --examine --scan >> /etc/mdadm/mdadm.conf
you need to update initramfs: to find the root raid
make sure these modules are included in /etc/initramfs-tools/modules
raid0 raid1 md
re-create inramfs:
update-initramfs -u -k all
check in /boot, if they got recreated!
dpkg-reconfigure mdadm
Check RAID Status:
watch -n1 cat /proc/mdstat mdadm --detail /dev/md2
Check Resync Speed Limits:
sysctl dev.raid.speed_limit_min sysctl dev.raid.speed_limit_max
Reconfigure Speed Limits:
sysctl -w dev.raid.speed_limit_min=50000 # increase speed -> higher system load sysctl -w dev.raid.speed_limit_max=5000 # lower speed -> less load, more time
Links: