Re: RN 516 - Remove inactive volumes to use the disk #4 – ghost volume

aequus · ‎2017-10-25

My device is running latest firmware 6.8.1 and has one raid 5 set of 6x6tb disk as data. Now the volume page shows disk 4 as a additional raid5 named data-1. On the message line appears “Remove inactive volumes to use the disk #4”. There is no error on the log tab, or the hardware display. After a reboot it looks again normal (no data-1) but after a while I have the same situation again.

What can I do to solve it without risking my data?

Sandshark · ‎2017-10-30

Yes, SDD (drive 4) is not a part ot MD126 (the second layer in your volume). Either the expansion did not go as it should when you added drive 4, or the NAS has "lost" that partition. But now it looks like it has found the lost partition and declared it to be a separate incomplete volume.

You may want to wait for @mdgm-ntgr or one of the other Netgear mods to concur, but it looks to me like that's exactly why they changed the OS to be more aggressive in looking for lost volumes and that deleting it will do the trick. Whether it will then re-sync and add the lost space into the volume is another thing. You may need to remove the drive, delete the partitions, and let it start from there. But that would be far less work that a factory default and restore.

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StephenB · ‎2017-10-25

Your data is already at risk; I recommend backing it up.

This particular issue is complex (has multiple root causes), so Netgear Support is in the best position to troubleshoot it. If you are the original purchaser, and purchased between 1 June 2014 and 31 May 2016 then you have free lifetime chat support for your NAS at my.netgear.com.

If you purchased new, but not within that timeframe, then you can still use paid support. Per-incident support is cheapers.

aequus · ‎2017-10-25

I have backups. I am the original purchaser I the device is from 2014 and registered. How can we proceed?

StephenB · ‎2017-10-25

As I suggested, IMO your best option is my.netgear.com.

BTW, I don't work for Netgear - just a member of the community.

Sandshark · ‎2017-10-25

It sounds like drive 4 has problems. Is it a "green" drive? They can cause this kind of problem. Anything you do has the potential to make matters worse, so having that backup is all important. If you don't have free chat and don't want to get paid support, there are a couple of things you can do. But don't do them unless you are prepared for the possibility you will lose the whole volume and have to re-build from scratch.

The first step is no risk. Download the system logs and look in the smart_history.log for any SMART errors and in system.log for any other clues.

If drive 4 does have errors, shut down the system and test the drive connected to a PC with manufacturer's tools (such as Seatools). It would be a good idea to test the rest, too. Make sure you keep track of which drive is which. Swapping out the wrong drive is one of the biggest risks if a replacement drive is called for.

If just one drive (4, probably) is bad, boot the system without that drive. It should come up and have just the one volume, but complain it is degraded.. Now buy a replacment and install it , with power on, in place of the removed drive and let it resync. There is some risk that another drive will fail during re-sync, which would kill your volume and you would need to replace that one as well and start from scratch with your NAS and backup.

This next step has the highest risk. If none of the drives come up as bad, you can still try booting without drive 4 since that's the one it's complaining about. Booting in read-only mode may reduce the risk. If that works, remove the partitions on the drive using a PC, and install it back in the NAS. You may have to re-boot out of read-only mode before adding the drive back -- I'm not sure. It will then resync as well. If you get errors during the sync process, then the drive probably just isn't going to behave well in the NAS.

I had this happen to one of my drives and, though Seatools said it was fine, it kept failing in the NAS. And it wasn't even a green drive.

aequus · ‎2017-10-26

Thanks for the tips I will do them as soon as possible. All drives are WD reds. The smartlog reports no error for all drives. It is strange the graphic I attached to my first statement shows drive 4 as separate volume data-1 but in the shell, there is no /data-1. Moving with the mouse over graphic of #1 it belongs to data. The performance of the nas is ok, I assume raid data is still working?!

Sandshark · ‎2017-10-26

What you are seeing usually comes from putting a drive from another NAS into the system without zeroing it first. The system sees that the used drive also has a data volume on it (though it may be incomplete), so it calls it data-1. So, your NAS thinks drive 4 is from another data volume.

Other things that are odd is that you don't seem to have the full 27.2TB that you should and that the data volume isn't complaining about being non-redundant. Did you grow the volume from some smaller drives? If drive 4 was previously a 4TB, the total space on data would be right. Maybe that accounts for there being unallocated space. I can't explain why drive 4 seems to be both a separate volume and also appears so keep the main volume redundant. Maybe something to do with layering, which also comes from growing from smaller drives.

Your NAS is clearly confused, which is why I warned that things could get worse. The only 100% solution would be a factory default, but it's worth trying some other things to keep from having to restore 20TB of data. You can always default later if needed.

What firmware did you update to 6.8.1 from? A few versions ago (6,7,something), the OS got more agressive at finding "lost" volumes so they can be deleted. Maybe you've always had this situation and just didn't know it. Has the space available always been what you see now? If that's the case, it may simply be safe to delete the phantom volume.

aequus · ‎2017-10-30

I started with 6x4tb WD reds and replaced them later one by one with 6 TB WD reds. All of the drives have never been in another nas. My phantom volume is shown with 7.28 TB this is more than the physical capacity of the 6TB drive.

My important data (less 1 TB) is backed on a daily base but the bulk of the data I am still transferring to my slow second nas. It will likely take three more days to finish. As soon as finish a will delete the phantom volume and will see what happened.

In a case I have to rebuild the complete /data raid set is there a change to keep config data

Sandshark · ‎2017-10-30

The reported size of the phantom does seem odd given where you stated and the current drive size. But when you look at the size of the other volume, maybe it makes some sense. Your main array is showing as if it were 5x6TB + 1x4TB. Do you know if it ever expanded properly to 27.2TB when you swapped the last drive? If it didn't (or it somehow got "undone"), then your second layer would be 5x2TB, about the size of the phantom. If it thinks the second layer on one drive is a part of some other 5x2TB volume, I suppose that could be it. Why it would think that, I can't say. If you can SSH in and execute an lsblk command, the results of that could be helpful in figuring it out. But I'm not sure it would be any more helpful in fixing it.

Yes, you can save and restore your configuration from the Settings page in case you have to factory default. But if you have any apps installed, make sure you re-install them before restoring the configuration.

aequus · ‎2017-10-30

here is the output of lsblk

NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT

sda 8:0 0 5.5T 0 disk

├─sda1 8:1 0 4G 0 part

│ └─md0 9:0 0 4G 0 raid1 /

├─sda2 8:2 0 512M 0 part

│ └─md1 9:1 0 2G 0 raid6 [SWAP]

├─sda3 8:3 0 3.6T 0 part

│ └─md127 9:127 0 18.2T 0 raid5 /data

└─sda4 8:4 0 1.8T 0 part

└─md126 9:126 0 7.3T 0 raid5

sdb 8:16 0 5.5T 0 disk

├─sdb1 8:17 0 4G 0 part

│ └─md0 9:0 0 4G 0 raid1 /

├─sdb2 8:18 0 512M 0 part

│ └─md1 9:1 0 2G 0 raid6 [SWAP]

├─sdb3 8:19 0 3.6T 0 part

│ └─md127 9:127 0 18.2T 0 raid5 /data

└─sdb4 8:20 0 1.8T 0 part

└─md126 9:126 0 7.3T 0 raid5

sdc 8:32 0 5.5T 0 disk

├─sdc1 8:33 0 4G 0 part

│ └─md0 9:0 0 4G 0 raid1 /

├─sdc2 8:34 0 512M 0 part

│ └─md1 9:1 0 2G 0 raid6 [SWAP]

├─sdc3 8:35 0 3.6T 0 part

│ └─md127 9:127 0 18.2T 0 raid5 /data

└─sdc4 8:36 0 1.8T 0 part

└─md126 9:126 0 7.3T 0 raid5

sdd 8:48 0 5.5T 0 disk

├─sdd1 8:49 0 4G 0 part

│ └─md0 9:0 0 4G 0 raid1 /

├─sdd2 8:50 0 512M 0 part

│ └─md1 9:1 0 2G 0 raid6 [SWAP]

├─sdd3 8:51 0 3.6T 0 part

│ └─md127 9:127 0 18.2T 0 raid5 /data

└─sdd4 8:52 0 1.8T 0 part

sde 8:64 0 5.5T 0 disk

├─sde1 8:65 0 4G 0 part

│ └─md0 9:0 0 4G 0 raid1 /

├─sde2 8:66 0 512M 0 part

│ └─md1 9:1 0 2G 0 raid6 [SWAP]

├─sde3 8:67 0 3.6T 0 part

│ └─md127 9:127 0 18.2T 0 raid5 /data

└─sde4 8:68 0 1.8T 0 part

└─md126 9:126 0 7.3T 0 raid5

sdf 8:80 0 5.5T 0 disk

├─sdf1 8:81 0 4G 0 part

│ └─md0 9:0 0 4G 0 raid1 /

├─sdf2 8:82 0 512M 0 part

│ └─md1 9:1 0 2G 0 raid6 [SWAP]

├─sdf3 8:83 0 3.6T 0 part

│ └─md127 9:127 0 18.2T 0 raid5 /data

└─sdf4 8:84 0 1.8T 0 part

└─md126 9:126 0 7.3T 0 raid5

Sandshark · ‎2017-10-30

Yes, SDD (drive 4) is not a part ot MD126 (the second layer in your volume). Either the expansion did not go as it should when you added drive 4, or the NAS has "lost" that partition. But now it looks like it has found the lost partition and declared it to be a separate incomplete volume.

You may want to wait for @mdgm-ntgr or one of the other Netgear mods to concur, but it looks to me like that's exactly why they changed the OS to be more aggressive in looking for lost volumes and that deleting it will do the trick. Whether it will then re-sync and add the lost space into the volume is another thing. You may need to remove the drive, delete the partitions, and let it start from there. But that would be far less work that a factory default and restore.

aequus · ‎2017-11-04

The backup and the resynch took a while. I pulled of the drive and deleted all volumes and inserted it again. The phantom volumen is gone and now I have around 2 TB more free space. Thanks for your assistance.

Sandshark · ‎2017-11-04

I'm glad it worked out.

I just want to caution others who may come searching for an answer to what looks like a similar problem that theirs might be different. This is not always the right action. If you cannot decypher the lsblk report, let somebody here take a look for you. Some months ago, another user deleted the wrong volume and lost everything.