Unable to mount RAID1 drive - System contains incomplete RAID group

[JeffryPaul]

I have a TS-453 Pro containing 4 drive bays, with two RAID-1 volumes. When a volume is full, I safely detach the volume and send each half of the mirror to separate locations for backup purposes.
If I need to recover data, I used to be able to insert one of the RAID-1 drives and mount the volume. The RAID1 volume is configured as a Static Single Volume.

The system is currently running firmware version 4.2.1. The error occurs with both 4.2.0 and 4.2.1

When I insert the RAID1 drive and scan the disks, I receive this message: [Storage Roaming] System contains incomplete RAID groups.
There are no volumes available to mount, so I cannot restore unless I have both disks of the RAID1 set.

What should I do to be able to mount and restore from a RAID-1 volume without needing both halves of the volume mounted?

[Spider99]

just to check i understand

1. you detach a disk from a raid1 and send that off site and replace it with another disk - periodically.

2. You do this for both raid volumes?

3. so you have 6 drives in total? - 2 in each raid and two offsite?

======
4. this process worked until you upgraded to 4.2.0?

5. Just out of interest how long have you been successfully doing this?

6. Do you have any "other" form of backup?

======
Although the problem experienced/query is not the same i would have a read of http://forum.qnap.com/viewtopic.php?f=25&t=122835 saves me having to type it out.
======
So are you effectively running on two broken raid1 with single disks? If so do a backup before you do anything else.

Let us know your answers and see if we can recover the situation. Others will chip in i am sure

[dolbyman]

the linked thread already says it, horrible "backup" strategy

[Don]

Sounds like the OP take both halves of the raid 1 out and sends them to different sites. So at times the default volume is completely removed. Even worse than horrible.

[JeffryPaul]

Unfortunately, the feedback received is irrelevant to the topic: why can't I restore half of a raid-1 mirror?
Anyone have a solution? QNAP?

[JeffryPaul]

Tim,

There are 4 drives, with each 2 drives created as RAID-1 volumes. The process did indeed work at one point, but appears to have stopped working with v4.2.0. It did work previously.
Regardless of whether I have other backups is irrelevant.

Why can't I recover from a broken RAID-1 mirror?

[Spider99]

Sorry but i am not confident i understand what the situation is

do you mean that you run on a single disk per volume then when you need to restore some data you go off site get the required disk and then pop it into the nas and want it to see the "new" disk and somehow rebuild?

If not could you explain in detail what you do and how it used to work please

[MrVideo]

Unfortunately, the feedback received is irrelevant to the topic: why can't I restore half of a raid-1 mirror?
Anyone have a solution? QNAP?

Go back to the firmware version the "worked."

It sounds like QNAP fixed a problem with what you were doing. RAID1 is not designed to do what you were doing. The fact that it worked previously, IMHO, is pure luck.

The correct procedure would be to back up the oldest data onto separately attached USB3.0 drives and then delete that data.

I'm sorry that you don't care for the responses, but you put yourself into this situation by doing something that the RAID architecture is not designed to do. The cure, going forward, is to revise your procedure and correctly back up your data. The truth can hurt.

[JeffryPaul]

you put yourself into this situation by doing something that the RAID architecture is not designed to do.

I'm expecting QNAP to abide by RAID architecture. Following standards, RAID-1 is recoverable with one failed/missing disk, just as RAID-5 is recoverable with N-1 disks. While I have not yet tested this scenario, QNAP may be requiring both bays to be populated (one from the RAID volume, one spare) instead of requiring only one drive to be mounted.
If this scenario doesn't work, then I agree that reverting to the older v4.1.4 QNAP firmware may be the only solution.

Regardless, I'll submit a support ticket with QNAP so they can look into this problem.

[MrVideo]

I suspect that part of the issue is that the missing drive wasn't "failed/removed" by the system. When you only have one drive installed, the NAS "believes" that it had two good drives and then complains about that.

[JeffryPaul]

I was able to recover the RAID-1 volume by adding a blank drive in addition to the broken mirrored drive.

[MrVideo]

FYI. for RAID1, one of the drives isn't really a mirror of the other. They are mirrors of each other. The new data is written to both drives at the same time.