Re: RAID 1 Issue - Volume Degraded after HDD replacement

risiman · ‎2017-04-25

I hava ReadyNAS 104 with firmware 6.6.1. Inside it I had 1 TB, 1TB, 3 TB and 6 TB HDDs, the two first configured as RAID 1.

I had a RAID 1 with 2 HDD of 1TB, but one of them stop working. While I receive a new one, a replace the broken one with a 2 TB HDD (I know I'm loosing 1 TB of space).

It was detected as part of the RAID 1, and started syncronizing. After it was sincronized, the HDD status change from SYNC to ONLINE, but the volume status is DEGRADED.

I think the problem is that the 2 TB HDD is set as SPARE instead of ACTIVE SYNC. If you get the raid detail you see that there are 2 working devices, but only 1 active devices. As you can see, the status is clean,degraded.

# /sbin/mdadm --detail /dev/md125
/dev/md125:
Version : 1.2
Creation Time : Thu May 28 13:29:45 2015
Raid Level : raid1
Array Size : 971912832 (926.89 GiB 995.24 GB)
Used Dev Size : 971912832 (926.89 GiB 995.24 GB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent

Update Time : Tue Apr 25 09:51:21 2017
State : clean, degraded
Active Devices : 1
Working Devices : 2
Failed Devices : 0
Spare Devices : 1

Name : 2fe53622:Personal-0 (local to host 2fe53622)
UUID : e9cdfd26:c97e9f56:51e0ac36:3c2bb179
Events : 116364

Number Major Minor RaidDevice State
0 8 51 0 active sync /dev/sdd3
2 0 0 2 removed

1 8 67 - spare /dev/sde3

Can anyone help me?

jak0lantash · ‎2017-04-25

I would unslot sde and reinsert it. This should trigger a new resync attempt and hopefully end up cleaning the RAID array.

Otherwise, manually operation may be necessary.

You should also consider backing up your data.

risiman · ‎2017-04-26

I've already tried that. I'm trying to resync the raid using an 1 TB new HDD, but it seams that the result will be the same.

Thanks

PD: Backup information will be a little complicated because I use iSCSi on that volume.

risiman · ‎2017-04-27

After new resync, same status.

jak0lantash · ‎2017-04-27

@risiman wrote:

PD: Backup information will be a little complicated because I use iSCSi on that volume.

You should always have a backup of your (important) data.

Try to reboot the NAS.

While technically "easy" to fix with the appropriate knowledge and access to the machine, it's very difficult to advise you on what to do as it creates a responsibility, and performing this kind of operation blindly is very risky.

If you want to learn how to fix it, research online about "mdadm".

Otherwise, you can full backup + Factory Default + restore.

Or contact NETGEAR Support to see if they can help you (it will most likely be paid Support).

risiman · ‎2017-04-27

I agree with you about doing backup, but I don't see a easy way to do the iSCSI volume backup.

I've reboot the NAS multiples times, and the result is always the same, the second disk starts sync, past to online, but raid is still degraded because the second disk remains in spare status.

Thank you anyway

StephenB · ‎2017-04-27

Can't you access the LUN from the client, and back it up from there?

risiman · ‎2017-04-27

That's what I'm doing now, but I'd be better to do it within the NAS, because It is not the same to backup the content of the iscsi lun than perform a backup of the LUN.

jak0lantash · ‎2017-04-27

@risiman wrote:
It is not the same to backup the content of the iscsi lun than perform a backup of the LUN.

Backing up the LUN container is one thing, but being able to restore the LUN container from a backup is another.

StephenB · ‎2017-04-27

@risiman wrote:

It is not the same to backup the content of the iscsi lun than perform a backup of the LUN.

That is true of course. But it is more efficient to back up its contents.