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Volume expansion seems inactive

xtrips1
Aspirant

Volume expansion seems inactive

Hello,

Volume expansion seems to be running for 2 days now but I have no sign of progress within the GUI.
See the HDD sizes and the actual disk space.
Something is wrong but I don't know what.

Someone told me to run this command to see if there is any progress

watch cat /proc/mdstat

I just don't understand the output of the command.
Any help please?

 

AND WHY MY SCREENSHOTS WON'T SHOW? 


net1.jpgNet 2.jpgNet 3.jpg

Model: RNDP600E|ReadyNAS Pro Pioneeer Chassis only
Message 1 of 16
mdgm
Virtuoso

Re: Volume expansion seems inactive

The screenshots aren't showing because images are reviewed by a moderator before they are published (just in case someone posts something inappropriate). Once a moderator approves them they will then show.

 

I can't see your screenshots, but what you are looking for is to see a resync with a percentage indicator of progress.

 

You can alternatively copy and paste the text from the output of

watch /cat/proc/mdstat

rather than post a screenshot.

The code tag option (see the </> button) is very good for posting that kind of output.

 

Say you are using X-RAID you would have md0 (4GB OS volume), md1 (swap) and md127 (data volume).

If you had say 3 disks installed and added a fourth you should see the 4th disk added to md0, md1 and md127. The md0 and md1 resyncs are very quick, but the md127 one would take a while.

If you replace a disk with a higher capacity disk, not only will md0, md1 and md127 need to be rebuilt, but if you have at least two disks of the higher capacity installed a new layer md126 would be added (note this is just an example md127 could be the new layer showing and md126 the one already present).

 

Once the resyncs have finished you should no longer see a rebuild status or percentage for any of the RAID arrays. The data volume should then expand provided your additions have met the requirements for expansion for the RAID level you have chosen.

 

If it doesn't expand you could see if a reboot helps.

Message 2 of 16
mdgm
Virtuoso

Re: Volume expansion seems inactive

Here's an example from a redundant single-layer volume with 6 disks:

 

root@MDGM-NAS:~# cat /proc/mdstat
Personalities : [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] 
md1 : active raid10 sdg2[5] sdf2[4] sdd2[3] sdc2[2] sdb2[1] sda2[0]
      1569792 blocks super 1.2 512K chunks 2 near-copies [6/6] [UUUUUU]
      
md127 : active raid6 sdg3[6] sda3[0] sdf3[5] sdd3[3] sdc3[2] sdb3[1]
      23422691328 blocks super 1.2 level 6, 64k chunk, algorithm 2 [6/6] [UUUUUU]
      
md0 : active raid1 sdg1[6] sda1[0] sdf1[5] sdd1[3] sdc1[2] sdb1[1]
      4190208 blocks super 1.2 [6/6] [UUUUUU]
      
unused devices: <none>
Message 3 of 16
xtrips1
Aspirant

Re: Volume expansion seems inactive

I am afraid that's chinese to me. 

I ran your command and got the screenshot enclosed. After reboot log says system is up and volume settings says status is redundant, appart from that the system totally disregards the amout of available space and is still stuck at a much lower value of disk space. No expansion. The GUI really lacks information.

Capture.JPG

Message 4 of 16
xtrips1
Aspirant

Re: Volume expansion seems inactive

I suppose my issue won't progress until the moderator unlocks my screenshots 😒

Message 5 of 16
xtrips1
Aspirant

Re: Volume expansion seems inactive

Finally the screenshots are here. Now you can review my issue. Can you help? And please layman words
Message 6 of 16
Sandshark
Sensei

Re: Volume expansion seems inactive

That mdstat output does not show any expansion still ongoing.  It shows you have four 3TB drives and two 4TB drives.  Is that accurate?  What was the previous configuration before the expansion?  I'm afraid I don't recall all of the expansion limits of RAIDiator 4.2.x, but you may have run into one of them.  @mdgm or @StephenB can help you more there.

 

There is some confusion in the answers because until the screen shots were shown, it was unclear if you were still running 4.2.x or had upgraded to OS6.

Message 7 of 16
xtrips1
Aspirant

Re: Volume expansion seems inactive

I think I get it. I have 3 X 3Tb HDDs and 3 X 4Tb HDDs. But historically I started the NAS with with 6 X 3Tb HDDs.
That little f***** stayed with 3Tb disks all the time, which explains why the volume shows a capacity of 14Tb.
Why did this happen? I thought the volume expansion was automatic. Obviously! Since there is nothing proposed about expansion in the GUI.
How do I solve that now? Or are my 3 extra terrabytes wasted forever?

Message 8 of 16
xtrips1
Aspirant

Re: Volume expansion seems inactive

OS6 ? Is there an upgrade path to OS6?
Anyway. At the beginning I had 6 X 3Tb HDDs. Gradually for each that failed a 4 Tb HDD replaced it. Now I am with 3 X 3Tb and 3 X 4Tb HDDs.

Message 9 of 16
Sandshark
Sensei

Re: Volume expansion seems inactive


@xtrips1 wrote:

I think I get it. I have 3 X 3Tb HDDs and 3 X 4Tb HDDs. But historically I started the NAS with with 6 X 3Tb HDDs.
That little f***** stayed with 3Tb disks all the time, which explains why the volume shows a capacity of 14Tb.
Why did this happen? I thought the volume expansion was automatic. Obviously! Since there is nothing proposed about expansion in the GUI.
How do I solve that now? Or are my 3 extra terrabytes wasted forever?


When you say you started with 6 x 3TB, you installed them initially or did a factory default with all installed, or did you start with fewer and add them along the way before switching to 4TB?  That's important for the expansion limitations, one of which is the volume cannot expand more than 8TB total.

 

If you have run into an expansion limit, then a backup, factory default, and restore is the only way around it.  You may then want to consider upgrading to OS6, which has no such limits.

.

Message 10 of 16
rn_enthusiast
Virtuoso

Re: Volume expansion seems inactive

@Sandshark 

This KB will describe the limitations incl. for OS 4.2: https://kb.netgear.com/7010/ReadyNAS-Volume-Expansion 

Former Netgear employee. Views and opinions are my own.
Message 11 of 16
xtrips1
Aspirant

Re: Volume expansion seems inactive

I don't exactly remember how I got there incrementally but that limitation seems to be exactly it.
I do not have the means to backup anywhere so I will have to pass on the expansion for now.
On the other hands I am interested to know how to upgrade to OS6 when the opportunity presents itself soon.
Is that something I can do? Or do I need a some Linux geek around, which I don't have?

Message 12 of 16
xtrips1
Aspirant

Re: Volume expansion seems inactive

I am thinking.... since I am not using the 4th Tb on those 3 HDDs.... could I just swap them one by one with 3Tb HDDs from my other NAS? Readynas will just "repair" using the 3 Tb HDD as if nothing happened right?
I know it will be tedious since I will have to rebuild with parity on both NAS machines for each swap but in the end I will make use of those extra terrabytes...

And one last thing not related, those Netgear HDD trays are really crap. It seems that they are cooked after many years. This is the second tray I ruined the locking mechanism. How do you open a stuck locked tray without exploding the whole plastic button and springs?

Message 13 of 16
rn_enthusiast
Virtuoso

Re: Volume expansion seems inactive

It is unfortunately not quite as simple as that. The NAS does a few things to produce its magic. It creates an underlying raid (using mdadm) and then sticks those raids together using LVM (Logical Volume Manager) and lastly it slaps a filesystem op top of all that. The system will expect a disk of same size or larger, you cannot replace with a smaller drive.

 

In order to bypass that you would need to mess with the LVMs and stuff. Not for the uninitiated and doing anything wrong at that level could comprise the entire data volume. If I were you, I would take this situation as an opportunity to consider investing in a second NAS that you can backup to (for the future as well). Then setup that second NAS and backup to it and the wipe the primary NAS once it is backed up (potentially install OS6 too, which is pretty painless - there should be several guides around and I think Sandshark did that before himself as well. He will know more about that than me anyway).

 

 

 

Former Netgear employee. Views and opinions are my own.
Message 14 of 16
xtrips1
Aspirant

Re: Volume expansion seems inactive

Mmmm more bad news from Netgear....
So you say if I remove a 4 Tb HDD, which actually is used as a 3 Tb HDD, and replace it with a real 3 Tb HDD, the NAS will reject it just because it found it "cozy" to get used to an extra Tb to waste? Smiley Wink

Message 15 of 16
Sandshark
Sensei

Re: Volume expansion seems inactive

Updating to OS6 is quite easy, and you will find instruction for doing so in multiple threads in the forum (try to find one from this year, as the location of the files needed has changed over time).  But step one is backing up all your data, since OS6 uses an entirely different file system and you can't simply migrate the intact volume.

 

As for downgrading back to 3TB drives.  The NAS has created a RAID from the extra 1TB sections of two of the three 4TB drives (md3 listed above).  I don't know what would happen if you were to replace either of them with a 3TB.  I suspect the NAS will complain, but I don't know enough about LVM to know if it could cause data loss if you replaced a second one.  One 4TB (presumably the last one you instered) has not had the additional 1TB added to a MDADM RAID, so I belive you should be able to return the original 3TB to that slot without issue.

Message 16 of 16
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