Talk:RAID upgrade

falcon upgrade

wot I done and when

for sdd

14:15 mdadm --fail /dev/md0 /dev/sdd2 mdadm --fail /dev/md2 /dev/sdd3 mdadm --fail /dev/md3 /dev/sdd4

[change hitachi physically]

14:40 - powerup 15:10 - finished partitioned OK and running... mdadm --add /dev/md0 /dev/sdd2 added as spare. mdadm --add /dev/md2 /dev/sdd3 syncing the mirror. ~20min mdadm --add /dev/md3 /dev/sdd4 syncing the raid5... starts at 15:33 - eta 220min (3h40min) ...finished at 19:10

====== then again, for sdc

19:15 mdadm --fail /dev/md0 /dev/sdc2 mdadm --fail /dev/md2 /dev/sdc3 mdadm --fail /dev/md3 /dev/sdc4

[change western digital physically]

19:55 - booted and partitioned mdadm --add /dev/md0 /dev/sdc2 added as spare. mdadm --add /dev/md2 /dev/sdc3 syncing the mirror. ~15min mdadm --add /dev/md3 /dev/sdc4 syncing the raid5... starts at 20:15 - eta 235min (3h55min) ...finished at 12:10

==== finishing up

• mkswap for sdc1 and sdd1, and swapon for each.

• grow md2 for /home

mdadm --grow /dev/md2 --size=max # executed when sdc4 was syncing. this sync then was DELAYED till that was done... ...approx 20 min. finished 12:30

pvresize /dev/md2 ...pvs now shows PV md2 for vg_home as having 96gig free :)

reboot ...md0 fails due to sdc2 and sdd2 superblocks looking far too similar! :( mdadm --zero /dev/sdd2 ...and it works. but lacking that one partition now! gar! ...ok, I think it's cos whilst sdc2 and sdd2 are technically set as mirrors, they have nothing syncd to them, no filesystem... (tune2fs was claiming it had nothing on there, even though it was spare. and still same even after it was sync'd to the live mirror by failing the other drives! grrrrr ...so, using mdadm --add to add the drive to the md0 ...and then using mdadm --grow -n 3 /dev/md0 - to make the drive an active mirror - forcing sync. ...same then for sdd2 - so it's a 4drive LIVE mirror - no spares. ...and reboot... = no did: mdadm --create --verbose /dev/md0 --level=mirror --raid-devices=2 /dev/sda2 /dev/sdb2 ...to recreate the superblock. a mirror with no spare yet ...and sda errors. GAR!!! ...turn off and on... ...ok ok ok I assembled from sdd2, since it was the only partition with the right uuid left, then added sd{a,b,c}2 in turn and that game them all the right uuid then grew to 2 devices (ie, shrunk it from 4 active) and then added the 2 devices back in - making them now spare, not active and finally mdadm --assemble --scan works let's see if it boots now! WOOT!

1. 1. 1. 1. 1. 1. 1. 1. 1. 1. what about sdc5 and sdd5

...a mirror? and then added to vg_shared? or left as the overload vg? (benefit of this is we restrict the space used which will make true expansion easier later on :) benefit to adding to vg_shared is havign space to snapshot straight awya problem is removing that pv later on when we wish to expand the original raid... ...otoh, seperate raid = no room for snapshots, but no pvreduce headaches...

• make it a mirror. the space will be reclaimed layer (when all four drives can expand the /shared across it), so for now the simplest thing is to make it a new mirror and not within lvm. (does this undermind the point of an LVM on /shared  ? maybe. In the long run I want to snapshot /shared anyway. we'll see :)

1. mdadm --create --level=mirror -n 2 /dev/md4 /dev/sdc5 /dev/sdd5

mdadm: array /dev/md4 started.

1. mkfs.ext3 /dev/md4
2. tune2fs -r 1 /dev/md4

...and mounted :)

1. 1. 1. 1. 1. 1. 1. not yet done ########

lvextend -L +50G -n lv_home vg_home resize2fs /dev/mapper/vg_home/lv_home script snapshots of lv_home for backup improvement :)