Resizing Raid-1 partitions.

rolgiati · 02-05-2023, 11:41 AM

After several years of using my PCLinuxOS/XFCE install, I find that the partitions sizes I settled on are not optimal: /var is too big, and /usr too small, probably because of all the progs I have been adding over the years.
Luckily the /var and /usr partitions are contiguous, which should simplify the process.

My idea is to boot a gparted live-cd/usb, shrink and move /var up, and expand /usr.

Since the partitions UUIDs remain untouched, mdadm.conf would remain unchanged.

Have I missed something ?

uteck · 02-05-2023, 04:35 PM

Seems like you have it, but first use Clonezilla or other tool to make a backup of the entire disk so you can restore if things do go wrong.
I have not done resizing on a system with RIAD, so I may be missing something.

syg00 · 02-05-2023, 05:00 PM

I would suggest read very carefully the supported features for gparted. It's a very good tool, but not (yet) magic.

You need to be cognisant of the separation of the filesystem from mdadm - they need to be managed separately and in the correct order. Especially when shrinking.
There are ways to do things as you describe, but you need the "magic" in place first - say btrfs/zfs or LVM RAID. For a "normal" mdadm setup, you have to do all the legwork correctly - quick search found this for example.

rolgiati · 02-06-2023, 04:00 AM

Quote:

Originally Posted by syg00

I always presume you have a verified B-A-C-K-U-P before taking any advice given.

Thank you for the kind advice.

Before making any change on one of the RAID HDs, I plan to clone it, so that if it comes to the worst, I can swap the un-modified clone to restore my system.