Replace Drive without Rebuilding Drive

[Adrian]

I recall doing this one with some help here, but I don't see the post in my history. Basically I'm upgrading a small drive with a larger drive, but I'm trying to avoid rebuilding the drive. I've excluded the drive from the shares and I've moved all the files off it. From what I recall there was a way to zero out the drive, remove the old drive and install the new drive and then I think you would tell unraid to accept the parity info or something like that. If anyone knows what I'm referring to please link/include the steps.

 

Thank you,

Adrian

Edited March 7, 2019 by Adrian
Wrong terminology

[JorgeB]

5 minutes ago, Adrian said:

Basically I'm upgrading a small drive with a larger drive, but I'm trying to avoid rebuilding parity.

You don't need to rebuild parity, just replace the smaller drive with the new one and let Unraid rebuild the disk, the other way is possible but much more work.

[trurl]

33 minutes ago, Adrian said:

I've excluded the drive from the shares and I've moved all the files off it.

And in fact no need to have done this either.

 

The whole point of parity is to allow you to replace/rebuild a failed or missing disk.

[Adrian]

50 minutes ago, trurl said:

And in fact no need to have done this either.

 

The whole point of parity is to allow you to replace/rebuild a failed or missing disk.

Yes, except it's going go through the process of reading all the drives to essentially rebuild an empty drive and that's what I was trying to avoid.

 

1 hour ago, johnnie.black said:

You don't need to rebuild parity, just replace the smaller drive with the new one and let Unraid rebuild the disk, the other way is possible but much more work.

Sorry, I typed it out really fast and worded it incorrectly. I've corrected my original post. Yes I know it's more work. There's a reason I wanted to do this, I've done it before. So if you know how let me know.

Edited March 7, 2019 by Adrian

[John_M]

I think this Alternate Procedure for Linux proficient users is what you're thinking of. Use it at your own risk.

 

[trurl]

2 hours ago, Adrian said:

Yes, except it's going go through the process of reading all the drives to essentially rebuild an empty drive and that's what I was trying to avoid.

But it was only empty because you emptied it. You could have just rebuilt it with the data still there and no need to go through all the writing of parity plus the destination disk to copy the data to the destination disk, then writing parity plus the source disk to delete the data from the source disk.

 

48 minutes ago, John_M said:

I think this Alternate Procedure for Linux proficient users is what you're thinking of. Use it at your own risk.

That procedure writes the entire disk and updates parity as it does, so it is still going to be doing a lot of work on at least those 2 disks, and may not be any faster.

 

A rebuild isn't really any more work than a parity check, maybe even less.

[Adrian]

12 hours ago, John_M said:

I think this Alternate Procedure for Linux proficient users is what you're thinking of. Use it at your own risk.

 

Thank you John, this is all I wanted.

[Adrian]

12 hours ago, trurl said:

But it was only empty because you emptied it. You could have just rebuilt it with the data still there and no need to go through all the writing of parity plus the destination disk to copy the data to the destination disk, then writing parity plus the source disk to delete the data from the source disk.

 

That procedure writes the entire disk and updates parity as it does, so it is still going to be doing a lot of work on at least those 2 disks, and may not be any faster.

 

A rebuild isn't really any more work than a parity check, maybe even less.

4x 2TB drives getting replaced by 1x 8TB drive. Lets ignore how the first drive is upgraded since you're caught up on the method used for that, ignoring the risks of losing a drive in the middle of this process. At some point 3x 2TB need to be removed from the server. Removing the drive and rebuilding parity doesn't provide parity protection during the process. Clearing the drive and then removing it provide parity protection during the entire process.

[JonathanM]

20 minutes ago, Adrian said:

4x 2TB drives getting replaced by 1x 8TB drive

Ahh, that makes the situation MUCH easier.

Add the 8TB drive to the array.

Leave all the original 2TB drives intact, COPY instead of move the data from the 2TB's to the 8TB. Exclude all the 2TB drives in question globally, and the data will be available over the network as soon as the copy is done.

Once all data is copied, set a new config and rebuild parity without the removed drives.

 

Parity is intact through the entire procedure until the data is safely copied to the new drive, and the data remains on the old drives as a backup even AFTER they are removed from the array.

 

MUCH safer, parity remains intact and you end the procedure with backups of your data.

[trurl]

49 minutes ago, Adrian said:

4x 2TB drives getting replaced by 1x 8TB drive.

Should have just said so at the beginning.