Hello,

One of my HDD failed, and is missing after reboot. Purchased a new one, server restarted and swapped disk 2. I'm trying to rebuild according to parity drive.

I've started in maintenance mode, and it was written that starting array will rebuild the disk.

1hour after it seems like nothing is happening.

A notification told me it's being reconstructed

But there is no writes to disk, and no reads to others.

Should I click "sync" to start data rebuild ?

Thanks everyone

Edited March 18Mar 18 by Trichelieu

Have you pressed the Sync button to start the rebuild?

Just now, itimpi said:

Have you pressed the Sync button to start the rebuild?

No, as I thought that starting array was going to rebuild automatically. (I misunderstood that ? It has just formatted drive to xfs ?)

Just now, Trichelieu said:

No, as I thought that starting array was going to rebuild automatically. (I misunderstood that ? It has just formatted drive to xfs ?)

It would start automatically if you restart the array in Normal mode. In Maintenance mode you need to press the Sync button.

1 minute ago, itimpi said:

It would start automatically if you restart the array in Normal mode. In Maintenance mode you need to press the Sync button.

Alright, pressed the sync button then, instantly rebulding disk !

Thanks, i preferred asking before making an error !

Have a nice day !

Just now, Trichelieu said:

Thanks, i preferred asking before making an error !

I agree that it is always a good idea if there is any doubt. We regularly see cases where someone makes an assumption and ends up doing something that stops an easy recovery from being possible.

Since you are doing this in maintenance mode, no way for us to know whether the emulated and now rebuilding disk is mountable. But I guess since you aren't overwriting the original disk, if it is necessary to repair the filesystem, it doesn't much matter whether you repair before or after rebuild.

7 minutes ago, trurl said:

Since you are doing this in maintenance mode, no way for us to know whether the emulated and now rebuilding disk is mountable. But I guess since you aren't overwriting the original disk, if it is necessary to repair the filesystem, it doesn't much matter whether you repair before or after rebuild.

Old disk was marked as missing. Couldn't mount it in anyway as it wasn't recognized at all.

There is a need to repair filesystem?

5 minutes ago, Trichelieu said:

Old disk was marked as missing. Couldn't mount it in anyway as it wasn't recognized at all.

Not talking about the physical disk. The emulated disk is what is being written to your rebuilding disk.

The contents of the emulated disk are calculated from the parity algorithm by reading all other disks. If the emulated disk is mounted, it is possible to read and even write to the "missing" disk, any writes being recovered by rebuilding. But we don't know if the emulated disk was mountable.

Did you notice whether it said unmountable when the disk became disabled?

If the rebuild is unmountable you will have to repair. We usually repair before rebuild, especially if overwriting the original disk.

11 minutes ago, Trichelieu said:

Couldn't mount it in anyway as it wasn't recognized at all.

Connection problems are much more common than bad disks.

20 minutes ago, trurl said:

Not talking about the physical disk. The emulated disk is what is being written to your rebuilding disk.

The contents of the emulated disk are calculated from the parity algorithm by reading all other disks. If the emulated disk is mounted, it is possible to read and even write to the "missing" disk, any writes being recovered by rebuilding. But we don't know if the emulated disk was mountable.

Did you notice whether it said unmountable when the disk became disabled?

If the rebuild is unmountable you will have to repair. We usually repair before rebuild, especially if overwriting the original disk.

Ok, thanks for the explanation.

If I remember well, old disk wasn't marked as unmountable. Just missing.

I'll see after rebuild if it's mountable.

19 minutes ago, trurl said:

Connection problems are much more common than bad disks.

Sure, tried to swap connections, same result.

Tried to put old disk in my other computer to read partitions, or anything : disk showed no sectors, nothing except its brand and model in recovery softwares.

Edited March 18Mar 18 by Trichelieu

25 minutes ago, Trichelieu said:

I'll see after rebuild if it's mountable.

After rebuild completes, start the array in normal mode. If the rebuilt disk shows SIZE, USED, FREE instead of Unmountable message it is OK.

18 hours ago, trurl said:

After rebuild completes, start the array in normal mode. If the rebuilt disk shows SIZE, USED, FREE instead of Unmountable message it is OK.

So array started in normal mode after rebuild : everything is in place 👍