mdadm how to stop a check
Is a mdadm check on your trusty software RAID array happening at the worst time and slowing down your server or NAS?
cat /proc/mdstat
Personalities : [raid1] [raid10]
md127 : active raid10 sdb4[0] sda4[1]
897500672 blocks super 1.2 2 near-copies [2/2] [UU]
[==========>..........] check = 50.4% (452485504/897500672) finish=15500.3min speed=478K/sec
........
mdadm force resync when resync=PENDING solution
cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md127 : active (auto-read-only) raid10 sdc1[0] sdb1[2]
1953382400 blocks super 1.2 512K chunks 2 far-copies [2/1] [U_]
resync=PENDING
bitmap: 15/15 pages [60KB], 65536KB chunk
Solution force repai........
mdadm how to stop or start a check
It's fairly simple to start or stop a check but I do wish mdadm's command had this built in. Sometimes it will do a check at the worst time causing the server to crawl to a halt.
Stop check on md126:
echo idle > /sys/block/md126/md/sync_action
Start check on md126:
echo check > /sys/block/md126/md/sync_action
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mdadm/md-check how to check array integrity without rebuilding
This doesn't seem to be widely known (maybe it's in some documentation that none of us read though)but there's an easy way to check the integrity of any mdadm array:
sudo echo check > /sys/block/md0/md/sync_action
-bash: /sys/block/md0/md/sync_action: Permission denied
sudo will never work, this only works as root since echo is not actually a binary/command. It is built-into bash.
/sys/devices/virtu........