Growing a RAID10 array with additonal devices

ferg

Hello all,

I've got a four drive (4 x 2TB) partitions in a RAID10 array (near copies)created by mdadm.

I would like to grow the array by two drives (all drives have a single partition).

Now I've grown RAID1 and RAID5 but never RAID10.

As I understand it I need to add the pair of drives together (mirrored stripes) and allow mdadm to deal with it. Once grown I can expand the EXT4 filesystem.

So my workflow would be to add the drives, grow the array and increase the number of active devices all in a single command.

So presuming the drives are all prepared then the mdadm command should be something along the following lines:

nvaert1986 · Tux's lil' helper Joined: 05 May 2019 Posts: 120

ferg · Posted: Fri Jun 04, 2021 1:17 pm Post subject:

Thanks. I think that man page is a little out of date though.
The array is fully backed up and umounted.
So I've just run:

ferg · Posted: Sat Jun 05, 2021 8:35 am Post subject:

It completed overnight.Now just to grow the filesystem.

I saw this post that indicates the release of MDADM 3.3 introduced the ability to reshaoe RAID10 devices.

https://superuser.com/questions/311570/adding-drives-to-a-raid-10-array

I also came across this comprehensive guide:

https://www.digitalocean.com/community/tutorials/how-to-manage-raid-arrays-with-mdadm-on-ubuntu-16-04

Cheers
Ferg
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