Re: Is shrinking raid5 possible?

[Goswin von Brederlow <goswin-v-b@web.de>]

Thomas Arthur Oehser <tom@toms.net> writes:

>> Putting swap in a raid-0 will hang your computer as soon as sda, sdb or  
>> sdc fails.
>> Are you OK with that?
>
> I'll move the swap to the partitions then, though it is a moot point as
> the machine has 4G physical RAM and runs with a load such that usually
> about 2G is cache... I assume that if it never swaps, it never matters.

Make it 2GB raid1 for swap then.

> But what I care about is the raid-5 shrinking issue... does anyone know
> if there is a reasonably safe way to shrink a raid-5 device (size, not
> number of drives) that is superblock format 0.90?  I assume the --grow
> just forces the superblock based on the _device_, but if I shrank the
> _device_ before I shrank the raid, it wouldn't find the superblock in
> the first place...
>
> -Tom

- shrink the raid
- fail+remove sda3
- make sda3 smaller
- add sda3 and resync
- repeat for sdb and sdc

You should have used LVM on your raid5. Makes suck things so much simpler.

MfG
        Goswin