Can't resize/increase RAID 1 static volume on my TS-239 Pro2

English Storage
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1

Hi

recently I upgraded my old 2-bay NAS, a TS-239 Pro 2, moving from a 1.5Tb raid 1 to a 4Tb raid 1, disk per disk, to avoid a fresh install.

Once sync was done, I decided to increase my static volume (it was still at 1.5Tb) to the max available (4Tb).

I tried with or without bitmap, same result :

Type Date Heure Utilisateurs IP Source Nom de l’ordinateur Contenu
Erreur 2026/06/10 12:03:02 System 127.0.0.1 localhost [Mirror Disk Volume: Drive 2 1] Raid Size Expansion failed.

I tried in command line, like mdadm --grow /dev/md0 --size=max
Same result too : no change but no error (echo $? = 0)

Honestly, I don’t know what to do more to increase my volume capacity. I know my NAS is old-fashioned but I do not intend to change it, it fits my needs since more than a decade.

I know that I can delete my volume, recreate a fresh new one et copy/paste my data from my previous disks. But I want to avoid this, or do it after tried everything else.

Thanks for your help

2

So that means you have no backups? You should take care of backups first, before you try anything else!

3

The size of static volumes can only be changed by adding drives, not by replacing them.

4

It’s not what I’m saying and this is not the question here. I’m perfectly aware about 3-2-1 backup strategy.

My offline/offsite backups are on my 4-bay NAS which is approx 100km away from my 2-bay. Got an ondemand vpn site 2 site to manage that replication. But it takes days for a full backup !

5

Hmmm … so with a 2-bay NAS, a RAID 1 volume, the only way to upgrade the volume size, is to destroy the previous one ? I’m quite surprise to be honest, and the GUI let me resize the volume, but it fails. Without logs, complicated to debug :confused:

I guess you are refering to How can I expand the Storage Pool/Static Volume by replacing the disks with larger capacity drives? | QNAP but it’s for QTS 4.3.4 or later. I’m still in QTS 4.2.6

Some pics :

Capture d’écran du 2026-06-10 16-30-36
Capture d’écran du 2026-06-10 16-30-36420×263 11 KB

Capture d’écran du 2026-06-10 16-30-56
Capture d’écran du 2026-06-10 16-30-56782×381 23.4 KB

6

No, that is not true

@charles_fr you should have a local backup then, if the other two are that cumbersome to get to

Also make sure you switch your UI from French to English before posting screenshots

md0 and your NAS model point to a legacy volume, so the guide about static volume expansion, I posted a couple of days ago, will not work on that

CAT1 devices need strict adherence to the swap process to work

7

I don’t understand what it means, sorry.

“Etendre la capacité” in French means “Expand capacity”

Where can I find some logs ? QTS 4.2.x is not using lvm to manage pv/lv/etc. right ? Which commands I can run to move forward and detect the bug I’m facing ?

8

Again, the size of static volumes can only be changed by adding drives.

See User Maunual.

9

User Manual oft QTS, not hero!!!

10

Not true, I have expanded the size of my old CAT1 legacy TS-419p+ and CAT2 NAS with static volumes many times, by upgrading the disks.

11

You need to announce each disk for swap before you swap the disks, otherwise capacity expansion will not be available in GUI (only true for these ancient CAT1 devices)

12

I’ve got your point, but how I can extend a RAID 1 volume with 2 different disk sizes ?

I come from 2*1.5Tb and I want to upgrade to 2*4Tb

Even if I change 1 disk, I can’t increase my RAID 1 volume to 4Tb, it’s the smaller disk which matters, am i wrong ?

I still have my older disks. And no new data since I plugged the 4Tb. I will test what you are saying.

13

You need to announce each disk before swap (do this via GUI) and then take the first disk out (the one you announced), erase it (external USB caddy in wndows with diskpart and ‘clean’ flag. Then reinsert the disk and rebuild. repeat it with the second disk and GUI will offer to expand the disk volume.

14

Hi

@dolbyman you were right, RTFM is always the rule 0 !

So, what I’ve done so far:

  • reinstalled my 2*1.5Tb
  • waited for the sync (again …)
  • asked for a resize, swapped the 1st disk
  • sync again
  • asked for a resize, swapped the 2st disk
  • sync again
  • asked for a capacity extension (to the max possible, so almost 4Tb)
  • sync in progress (currently 47% done in 8h)

It’s under good way, this evening my volume will be increased as I wish.

Thanks guys

++

15

Talked to fast. Expansion failed after 9h …

17

As your machine is quite old, would you consider just backing up your data and rebuilding the RAID from scratch?

18

I wanted to avoid that, but I can’t know ignore the fact I will have to do it. Not really a big deal btw. Just need to find where I parked my usb hdd reader ^^

19

Hi

Give some news. It was my last option I wanted to choise, but this is this one which allow me to upgrade my RAID 1 to 4Tb.

So, I delete the former volume, create the new one, and recopy all my data from one of my older 1.5Tb disk.

Works almost like a charm ! I don’t remember how many hours it took to recopy my data (I used the NAS external USB port)

The sync with my remote TS470-RP f(full backup) took almost 2 days !!