On Sun, 10 Apr 2011 00:14:56 +0800 Brad Campbell <lists2009@xxxxxxxxxxxxxxx> wrote: > 1 - When adding 2 missing disks to a RAID-6 (let's say a 4 drive RAID-6 > that was created with only 2 disks initally) why does it sync the first, > then sync the second rather than doing both together? > ie mdadm --add /dev/md0 /dev/sd[ab] Because the devices are added one at a time and between the moment when sda is added and when sdb is added a recovery starts. mdadm should write 'frozen' the 'sync_action' before adding the devices, and then 'idle' after adding them both. But it doesn't yet. You could... echo frozen > /sys/block/md0/md/sync_action mdadm /dev/md0 --add /dev/sd[ab] echo idle > /sys/block/md0/md/sync_action NeilBrown > > 2 - If a drive disappears how do I remove it from an array. > Let's say I have a 10 drive RAID-6 that has an odd error on a disk. > The disk goes away (sdl), the disk comes back as sdq as md is still > hanging on to the name sdl. I add sdq to the array, but I can't remove > sdl as it physically no longer exists. udev has removed the device node > and mdadm can't remove it from the array as it can't tell what it was. > > Like this : > Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] > md0 : active raid6 sdq[10] sdc[0] sdd[6] sdl[1](F) sdh[9] sda[8] sde[7] > sdg[5] sdb[4] sdf[3] sdm[2] > 7814078464 blocks super 1.2 level 6, 64k chunk, algorithm 2 > [10/10] [UUUUUUUUUU] > > Nothing urgent, just musings after the last weeks oddities. > > Regards, > Brad > -- > 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
