Unmountable Drive in Cache Pool

[shooga]

My server has become unresponsive 2-3 times in the last few months, which requires me to do a hard restart (hold the power button down). Clearly I need to figure this issue out, but I'll do that separately. After the latest hard restart I have a drive in my cache pool (2 drive pool) that is unmountable. I have read the FAQ about using restore and repair, but I have some questions:

 

1. I have a backup and have done a restore to an array folder, but isn't my data safe on the other drive in the pool?
2. Shouldn't I be able to repair (or even replace) the unmountable drive and then rebuild the pool from the working pool drive? How does that process work?

 

Thanks!

[JorgeB]

5 minutes ago, shooga said:

I have a backup and have done a restore to an array folder, but isn't my data safe on the other drive in the pool?

Maybe yes, maybe not, you'd need to try one device at the time, most likely either one by itself would remain unmountable.

 

6 minutes ago, shooga said:

Shouldn't I be able to repair (or even replace) the unmountable drive and then rebuild the pool from the working pool drive? How does that process work?

Not when the filesystem is damaged, unless using just one of them works, then you'd add the second device again, after completely wiping it first.

 

Pool redundancy is mostly to protect against a failed device, not a corrupt filesytem, same thing for parity in the array, it usually can't do anything for a corrupt filesystem on a data disk.

 

[shooga]

How would I try using just one device on its own? I've tried taking the array offline and removing a cache drive, but that doesn't seem to work and I can't tell if that's just because I'm doing it wrong or because both drives are corrupt.

 

When I try to add my cache drive back to the pool it sees it as a new device and I get a warning that all data will be overwritten. Can't tell if that means both drives will be empty or if the pool will be rebuilt.

 

Thanks again.

[JorgeB]

17 minutes ago, shooga said:

I've tried taking the array offline and removing a cache drive, but that doesn't seem to work

That's all you need to do, but like I said they most likely won't work individually in case of fs corruption, since it affects both devices.

 

18 minutes ago, shooga said:

When I try to add my cache drive back to the pool it sees it as a new device and I get a warning that all data will be overwritten. Can't tell if that means both drives will be empty or if the pool will be rebuilt.

In this case it means the added device would be overwritten with the data from the existing one, but since the pool doens't mount nothing will be done.

[shooga]

Thanks for your help. I was able to rebuild my pool and get everything back up and running. Thankfully I was using the CA Backup plugin.

 

I was really under the assumption that an issue like this would have been protected, but I understand now.