X-Raid 2 Expansion doesn't take place

Dear Community,

Yesterday I replaced a 1.5TB drive with a 4TB drive and expected that the volume would increase at least somewhat. However, after lots of resyncing, that hasn't happened. I would be very happy if anybody had an idea why not. Logs don't indicate any errors, so I assume it has to do with some sort of internal limitation.

Below screenshots illustrate the current situation, I can supply more info if needed, of course.

Appreciate any help.

Thanks in advance,

Gunnar

Adding Disks

StephenB
Apr 28, 2018
Here are your data volume RAID groups:
md6 : 2930252352 blocks
md5 : 1953500928 blocks
md4 : 2441879280 blocks
md3 : 2441879280 blocks
md2 : 2418326480 blocks

While this doesn't give us the details of the expansion history, it does tell us that over time you've had 500GB, 1 TB, 1.5TB, 2 TB, and 3TB drives in the system (as well as the 4 TB drive you have in now).

These RAID groups total to the right volume size (~11.35 TiB), so the expansion problem is with the ext file system, not the RAID array itself.

Your NAS has two expansion limits:

A volume can't expand over 16 TiB

A volume can't expand more than 8 TiB from it's original starting size.

The first limit doesn't apply to you, since your volume size is well under 16 TiB. However, the second limit could apply. Please open expansion.log in the log zip file, and search for the first occurence of The filesystem on /dev/c/c

The block size on that line should be the starting size of the array. You can check the date also, and see if that aligns to the initial install (or the last factory default).

If you have hit that threshold, you'll need to back up your data and do a factory default with all disks in place. Reconfigure the NAS and restore the data from the backup. You could also convert your NAS to OS-6 while you are at it - it doesn't have these expansion limits.

4 Replies

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StephenB
Guru - Experienced User
Apr 28, 2018
It should expand to about 11.3 TiB.

But it looks to me like expansion might have failed once before, since 3x3TB+2x1.5TB+2 TB should have given you a 10 TiB volume, not 9.

Can you give us some details on the expansion history (what disks you had installed at the last factory default, and what you've done since then)?

You could also download the log zip file, and post mdstat.log. You can't attach it, but you can copy/paste the text.
gunnark
Aspirant
Apr 28, 2018
Personalities : [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md6 : active raid5 sda9[0] sde9[3] sdb9[2] sdf9[1]
2930252352 blocks super 1.2 level 5, 64k chunk, algorithm 2 [4/4] [UUUU]

md5 : active raid5 sdd8[0] sde8[4] sdb8[3] sda8[2] sdf8[1]
1953500928 blocks super 1.2 level 5, 64k chunk, algorithm 2 [5/5] [UUUUU]

md4 : active raid5 sde7[7] sdb7[6] sda7[5] sdf7[4] sdd7[3] sdc7[2]
2441879280 blocks super 1.2 level 5, 16k chunk, algorithm 2 [6/6] [UUUUUU]

md3 : active raid5 sdc6[5] sdd6[7] sde6[6] sdf6[8] sdb6[10] sda6[9]
2441879280 blocks super 1.2 level 5, 16k chunk, algorithm 2 [6/6] [UUUUUU]

md2 : active raid5 sda5[10] sdf5[9] sde5[7] sdd5[8] sdc5[6] sdb5[11]
2418326480 blocks super 1.2 level 5, 16k chunk, algorithm 2 [6/6] [UUUUUU]

md1 : active raid6 sda2[0] sdf2[5] sde2[4] sdd2[3] sdc2[2] sdb2[1]
2096896 blocks super 1.2 level 6, 64k chunk, algorithm 2 [6/6] [UUUUUU]

md0 : active raid1 sda1[10] sdc1[6] sdf1[9] sde1[7] sdd1[8] sdb1[11]
4194292 blocks super 1.2 [6/6] [UUUUUU]

unused devices: <none>
- StephenB
  Guru - Experienced User
  Apr 28, 2018
  Here are your data volume RAID groups:
  md6 : 2930252352 blocks
  md5 : 1953500928 blocks
  md4 : 2441879280 blocks
  md3 : 2441879280 blocks
  md2 : 2418326480 blocks
  
  While this doesn't give us the details of the expansion history, it does tell us that over time you've had 500GB, 1 TB, 1.5TB, 2 TB, and 3TB drives in the system (as well as the 4 TB drive you have in now).
  
  These RAID groups total to the right volume size (~11.35 TiB), so the expansion problem is with the ext file system, not the RAID array itself.
  
  Your NAS has two expansion limits:
  
  A volume can't expand over 16 TiB
  
  A volume can't expand more than 8 TiB from it's original starting size.
  
  The first limit doesn't apply to you, since your volume size is well under 16 TiB. However, the second limit could apply. Please open expansion.log in the log zip file, and search for the first occurence of The filesystem on /dev/c/c
  
  The block size on that line should be the starting size of the array. You can check the date also, and see if that aligns to the initial install (or the last factory default).
  
  If you have hit that threshold, you'll need to back up your data and do a factory default with all disks in place. Reconfigure the NAS and restore the data from the backup. You could also convert your NAS to OS-6 while you are at it - it doesn't have these expansion limits.
  - gunnark
    Aspirant
    Apr 29, 2018
    Hi Stephen,
    
    thanks, you are right, the filesystem was 1456603136 blocks originally. Assuming a blocksize of 1k that fits with the expansion limit.
    
    I will follow your advice regarding the upgrade.
    
    Thanks a lot,
    
    Gunnar