On 25/02/2010 17:41, Dawning Sky wrote:
On Thu, Feb 25, 2010 at 8:45 AM, John Robinson
<john.robinson@xxxxxxxxxxxxxxxx> wrote:
On 25/02/2010 08:05, Giovanni Tessore wrote:
[...]
I do think we urgently need the hot reconstruction/recovery feature, so
failing drives can be recovered to fresh drives with two sources of data,
i.e. both the failing drive and the remaining drives in the array, giving us
two chances of recovering every sector.
I was one of those 4 cases in the part month. I would have certainly
benefited from this when I tried to replace a failing drive on my old
raid-5. But I think actually the redundancy you desired can be
achieved by running a raid-6 at the degraded mode (with 1 missing
drive).
Do I miss something? If this is the case, shouldn't we all
be doing this instead of using the raid-5?
I think you must be missing something, yes. RAID-6 with one drive
missing would have 2 chances of recovering each sector, but then so does
RAID-5 with no drives missing. In either case, lose a drive and you need
every sector on the remaining drives to be good to complete the
reconstruction and keep the array up.
Cheers,
John.
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