You could also use mdadm..... :-) Say you have raid10 array md0 with members sda1 sdb1 sdc1 sdd1 and you wish to swap out sdd1 for sde1, with as little time for massive fail as possible...: Add a bitmap (bitmap chunk may need tweaking here depending on size of devices) mdadm -Gb internal --bitmap-chunk=1024 /dev/md0 Fail and remove device: mdadm --fail /dev/md0 /dev/sdd1 mdadm --remove /dev/md Build (NOT create) a new raid1: mdadm --build /dev/13 -ayes --level=1 --raid-devices=2 /dev/sdd1 missing Add this new raid1 to md0: mdadm /dev/md0 --re-add /dev/md32 Add the new disk to the temp raid1: mdadm /dev/md32 --add /dev/sde1 [Now wait a while for md32 to resync. md0 should not have had to resync at all if the array was not in use. Hurrah bitmap!] Remove the raid1: mdadm /dev/md0 --fail /dev/md32 mdadm /dev/md0 --remove /dev/md32 mdadm --stop /dev/md32 Re-add the new disk mdadm /dev/md0 --re-add /dev/sde1 Zero superblock of old disk mdadm --zero-superblock /dev/sdd1 2009/10/3 David Rees <drees76@xxxxxxxxx>: > (Re-adding linux-raid to CC) > > On Fri, Oct 2, 2009 at 6:36 PM, Ryan Wagoner <rswagoner@xxxxxxxxx> wrote: >> On Fri, Oct 2, 2009 at 2:22 PM, David Rees <drees76@xxxxxxxxx> wrote: >>> It seems like I should be able to add a drive as a directly >>> replacement for one of the drives I'm pulling out (so I temporarily >>> end up with 3-copies of that chunk instead of 2) until I pull >>> fail/remove the older disk. If I was using RAID0 striped over RAID1 >>> mirrors, for example, I know this is possible. >>> >>> Is this possible to do with RAID10? >> >> You could stop the array and use dd to copy the old disks to the new >> ones. Then just start up the array on the new disks. > > Yeah, that would work, but the goal is to do the migration without any downtime. > > eSATA hot-swap even in inexpensive enclosures works pretty well these > days. There are slight hiccups as the drives get rescanned, but it's > not too noticable. > > -Dave > -- > 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 > -- 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
