On 2013-09-14 4:50 AM, Grant <emailgr...@gmail.com> wrote:
http://blog.open-e.com/why-a-hot-spare-hard-disk-is-a-bad-idea/
"Based on our long years of experience we have learned that during a
RAID rebuild the probability of an additional drive failure is quite
high – a rebuild is stressful on the existing drives."
This is NOT true on a RAID 10... a rebuild is only stressful on the
other drive in the mirrored pair, not the other drives.
But, it is true for that one drive.
That said, it would be nice is the auto rebuild could be scripted such
that a backup could be triggered and the auto-rebuild queued until the
backup was complete.
But, here is the problem there... a backup will stress the drive almost
as much as the rebuild, because all the rebuild does is read/copy the
contents of the one drive to the other one (ie, it re-mirrors).
Instead, how about a 6-drive RAID 10 array with no hot spare? My
guess is this would mean much greater fault-tolerance both overall and
during the rebuild process (once a new drive is swapped in). That
would mean not only potentially increased uptime but decreased
monitoring responsibility.
I would still prefer a hot spare to not... in the real world, it has
saved me exactly 3 out of 3 times...
