Re: My MD is too big to resize ext4.

[Wols Lists <antlists@youngman.org.uk>]

On 08/07/17 01:41, Ram Ramesh wrote:
> Hi,
> 
> I asked in other linux forums and did not get enough info. So I come
> here even though this is not mdadm/RAID issue.
> 
> I replaced 3TB disks in my 6-disk RAID6 with 6TB and now my md0 is 24TB.
> I had 32bit version of ext4 on it which can only be grown to 16TB. Any
> one had this issue before and any _/inplace/_ good solution to grow ext4
> to full 24TB? It is unlikely that I will be able to back up and recreate
> file system.
> 
> My filesystem is on md0 drive so I guess partitioning and making into 2x
> 12TB ext4 will not work. I am not even sure if we can partition md like
> any other disk.

You can partition an array and create partitions in it - caveat I
haven't done it, and I've never seen anyone here mention that they've
done it - lvm seems to be the more popular version.
> 
> On the web, I only found one solution that required upgrading kernel to
> some very recent one (not in my distro) and getting the bleeding edge
> resize2fs. This makes me nervous. Is there a solution that avoids this.
> 
resize2fs is bleeding edge? I suspect it's v0.99 quality, ie nobody has
the nerve to upgrade it to v1, despite it being rock solid. I know I've
used it without trouble. Most of these utilities are pretty solid
(unless the underlying filesystem itself is experimental ...)

Cheers,
Wol