On Wed, Nov 30 2016, Patrick Dung wrote:
Hello,
As I know if MD raid is using the newer metadata version, it support
resumable raid rebuild/sync. (that is, if a server is rebooted during
rebuild, it would resume from last position after reboot, instead of
starting from beginning).
In my recently testing (a few months ago):
I sometimes use the mdadm 'check' action for doing the disk scrubbing
of a MD raid.
After I rebooted the server, the 'check' operation is forgotten and is
not resumable.
I think resumable 'check' operation is useful as the array size would
become bigger in the future.
"check" is resumable. md doesn't record where it is up to though, you
need to do that yourself.
The "misc/mdcheck" script in the mdadm package makes use of this to
support time-limited checking, and to resume from where it left off.
You could use the script, or read it and see how it works.
NeilBrown