How to force expansion in RAID-X after disk addition?

[nglshmn]

I have an RN31400 using X-RAID and the latest firmware (6.9.1).

I had 4 disks, 8T8, 8Tb, 6Tb & 6Tb.

I replaced the third disk with an 8Tb one, meaning I now have 8Tb, 8TB, 8Tb & 6Tb. All are WD disks on the compatibility list and are recognized fine.

Using the RAID-X calculator I should have more than the 14Tb of available space, shouldn't I?  It didn't increase when I swapped the 3rd disk out. It is set to RAID-X and reports RAID-5. No snapshots.

Apart from factory reseting it, is there a way to force expansion?  I've rebooted it, balanced it and rebooted again several times to no avail.

[nglshmn]

Sorry, 15.5Tb, not 14Tb of available space.

[Sandshark]

Did you start with all 6TB's?  It sounds like it's only using 6TB on all of your drives.  Is XRAID enabled?  That would be the case for Flex-RAID.

Do ou have SSH enabled and can you go in and execute lsblk?  That will show you what partitions on what drives are included in your volumes.  Post results here if you need help interpreting them.

[nglshmn]

No, the two 8’s and the two 6’s. They weren’t XRAID, so converted to that first. That’s obviously where the problem occurred. Th question is, apart from a fresh reset again, can I force it to do XRAID properly?

I think I can SSH in, but what will that show me? Can I then use a command to fix it?

Thanks.

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[StephenB]

You should have had a 20 TB (~18 TiB) volume before you upgraded the disk.

Do you recall what RAID mode you were running before you switched to XRAID?

[nglshmn]

I uploaded my SSH oputput, but it seems to have disappeared!

The issue seems to be that there were multiple RAID arrays - I think it must have been in Flex-RAID format. I removed a disk and replaced it with a bigger one, but just as it was rebuilding it said there were several RAID.  Once it had rebuilt I changed it to XRAID. I guess I should have done the conversion before removing the disk.

If there's no specific command to force expansion or somehow work out whixh RAIDs to remove, then I'm supposing the only option is a wipe and rebuild, which is a pain in the $#@#$, but I have a backup. Here goes my weekend....

[StephenB]

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@nglshmn wrote:

I uploaded my SSH oputput, but it seems to have disappeared!

Maybe try again. It might have gotten stuck in the spam filter. It's not there now, but there's a lot of spam and it might have been deleted accidentally.  You could also try posting a screenshot of the volume tab of the web ui.

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@nglshmn wrote:

The issue seems to be that there were multiple RAID arrays - I think it must have been in Flex-RAID format.

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Since you have unequal size disks, even XRAID would give you at least two RAID groups (md126 and md127), which would be concatenated into a single volume.

What is the expansion history?  In particular, did you add the 6 TB drives after the 8 TB or before?

[nglshmn]

OK, so went the hard route and wiped everything.  Created a new Data Volume using the three 8Tb disks in X-RAID format (Slots 1x1, 2x1 and 3x1). Waited a week to resync data!

Put in the 6Tb disk (in slot 4x1) and it just sits there blacked out. Rebooting does not force an expansion. Even clicking on that blacked-out disk and invoking X-RAID, or formatting it doesn't force an expansion after a reboot. Now what? How do I force it to use that additional disk?

[mdgm-ntgr]

To expand a volume you need to use a disk with at least as much capacity as the existing disks. So you'll need an 8TB disk not a 6TB one.

[nglshmn]

How does it decide what is the 'correct' disk size to default on? The largest disk, or the size of the largest number of disks?

If I had made this array 6Tb, 8Tb, 8Tb, 8Tb (in that order), would I have gotten a bigger array than 3 x 8Tb?

I'm confused how to maximize the array size as I buy bigger disks, as I can't afford to buy them four at a time!

Thanks.

[mdgm-ntgr]

The smallest disks need to be put in the NAS first. So if you started off with the 6TB disk in the NAS you'd get a 4x6TB RAID-5 layer and a 3x2TB RAID-5 layer with 1x6TB and 3x8TB disks installed using the default X-RAID2 single-redundancy.

[nglshmn]

Thanks MDGM. That point had escaped me completely.  New disk on order...

[StephenB]

Also, if you are using single redundancy...

If you want to upgrade the disk sizes, you need at least two disks of the largest size in order to see an increase in capacity.