Replace drive without any risk

[krisha]

As i understood the regular way to replace a (good) drive is to remove it from the controller and let unRAID rebuild it.

 

But if something happens to the array during this time, what will happen?

 

Can I just connect the old drive again and it will work? I saw around 8-9 writes to the data drives during a parity sync.

 

Best way probably is to just clone the drive before. Is this supported? What happens if the drive is larger in size?

 

I'm currently replacing the parity and I take the risk. But maybe it would be nice feature to implement.

[daniel.boone]

Never tried but I'm thinking you can recover if you have the pre upgrade drive settings saved from the usb drive.

 

I'm guessing you can't go backwards without them. Anybody with 2 USB drives willing to test?

[lionelhutz]

I recently helped someone who had a failed drive also knock another one out of the array. With 1 real failed drive and the array thinking there were 2 "failed" drives it would not allow a rebuild and he couldn't just reset the array without losing the data from the failed disk. So, we put a partition on the replacement disk and then initialized unRAID but told it to build the failed disk instead of parity. He reported that it worked great and all the files he checked were good. So, there are options but it depends on the failure mode.

 

There is no reason you couldn't do a similar thing by putting the replaced drive back and then rebuilding the other one that failed. No guarantees though and don't write to the array during a rebuild.

 

Peter

[Rajahal]

The Trust My Array procedure can also come in handy sometimes during these tricky situations.  However, as long as you run regular parity checks (the monthly parity check add-on is nice for this) and keep an eye on your SMART reports (myMain helps with this), then a multiple disk failure is unlikely.

[lionelhutz]

The Trust My Array procedure can also come in handy sometimes during these tricky situations.  However, as long as you run regular parity checks (the monthly parity check add-on is nice for this) and keep an eye on your SMART reports (myMain helps with this), then a multiple disk failure is unlikely.

 

Yes, it could help put the old drive back if the other drives were still healthy. It would be no help if another drive failed during the replacement drive rebuild. What I mentioned was very similar, you just change the 99 to the disk number you need to rebuild. Just NEVER intentionally try to bypass the interface and do this to replace a disk because it won't work unless you first put a valid unRAID partition on the disk.

 

Peter