On Wed, 2006-04-19 at 10:41 -0700, Brendan Conoboy wrote: > Ming Zhang wrote: > >> Why can't you just mark that drive as failed, remove it and hotadd a > >> new drive to replace the failed drive? > > > > because background rebuild is slower than disk to disk copy, since his > > disk is still fully functional. > > Wouldn't it be great if every disk in a RAID volume were in its own way > a degraded RAID1 device without a mirror? Then when any drive started > generating recoverable errors and warnings a mirror could be allocated > without any downtime. You can certainly generate a layout like this > manually, but it would be nice to have that sort of feature out of the > box (and without the performance hit!). This would help a great deal in > a situation such as Dexter's. is this possible? * stop RAID5 * set a mirror between current disk X and a new added disk Y, and X as primary one (which means copy X to Y to full sync, and before this ends, only read from X); also this mirror will not have any metadata or mark on existing disk; * add this mirror to RAID5 * start RAID5; ... mirror will continue copy data from X to Y, once end * stop RAID5 * split mirror * put DISK Y back to RAID5 * restart RAID5. since this is a mirror, all metadata are same. it will be even greater if no need to stop raid5 to do this. may MD already can do this, but I do not know. > > -Brendan (synk@xxxxxxxx) - 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
