Neil Brown wrote:
(...)
Which starts a resync of drives. As one can imagine, resync of 800 GB on
a rather slow device (600 MHz ARM) can take 12 hours or so...
I believe that was intended to be once a month, not once a day.
Slight error in crontab.
So my question is: is this "daily forced resync" necessary?
Daily is probably excessive, certainly on an array that size.
Monthly is good. Weekly might be justified on cheap (i.e. unreliable)
drives and very critical data.
With RAID, sleeping bad blocks can be bad. If you hit one while
recovering a failed drive, you have to put the piece back together by
hand.
A regular check can wake up those sleeping bad blocks.
Thanks a lot for clarification.
When can one need to run a "daily forced resync", and in which
circumstances?
As I said, I think the 'daily' is an error. What exactly do you have
in crontab??
Indeed, the crontab entry is wrong:
# by default, run at 01:06 on the first Sunday of each month.
6 1 1-7 * 7 root [ -x /usr/share/mdadm/checkarray ] &&
/usr/share/mdadm/checkarray --cron --all --quiet
However, it will run at 01:06, on 1st-7th day of each month, and on
Sundays (Debian etch).
--
Tomasz Chmielewski
http://wpkg.org
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
