Replacing Data Drive (6.12.4)

[shazza6887]

Hi all!

 

I am wanting to start replacing some data drives one by one every few months with 10tb ones, some are approaching 7 years old and whilst i currently have no bad sectors on them i want to get a head start! I have an array of 8 drives (non hot swap) 2 drives are 10tb Parity drives that are about a year old. The other 6 data drives are 8tb.

 

Am i good to just stop the array, turn off the servers, swap the disc out with the new one,  when the server starts make sure auto start array is off, preclear the disc whilst the array is idle, after preclear select the new disc and let the array rebuild/re sync?

 

Is a preclear still best practice? Should i be good with 2 parities to be doing this not really concerned?

 

I have seen people empty the disc using unbalance first but that seems a bit tedious and unnecessary ?

 

Thank you for all the advice and ongoing support!

[itimpi]

7 hours ago, shazza6887 said:

Is a preclear still best practice? Should i be good with 2 parities to be doing this not really concerned?

It is really up to you.   When doing a replacement a pre-clear just allows a stress test of the drive before using it in anger.  It does not otherwise affect the replacement process as that overwrites every sector on the replacement drive anyway.   

 

This is different to adding the drive as a new drive to a new slot as then the pre-clear can run asynchronously to adding it thus speeding up the add process so there is more to gain (although still strictly speaking not necessary).

 

7 hours ago, shazza6887 said:

have seen people empty the disc using unbalance first but that seems a bit tedious and unnecessary ?

 

I agree this seems unnecessary in a case where you are replacing a drive that you believe is still good.    Just keep the drive that is being replaced intact until the rebuild onto the new larger drive has completed successful.

[shazza6887]

ty!

 

So if a drive is still good and you simply take it out to replace it with a larger one, if anything does happen wold that prior working drive be able to simply put back into the array in its prior position? I did not know that was the case?

[JonathanM]

12 hours ago, shazza6887 said:

ty!

 

So if a drive is still good and you simply take it out to replace it with a larger one, if anything does happen wold that prior working drive be able to simply put back into the array in its prior position? I did not know that was the case?

Not that simple, but if the drive is good, then you can at least read all the files and compare them with what was rebuilt on to the new drive.

 

If you rebuild on to a larger drive, Unraid won't then accept a smaller drive in that slot without doing a new config and rebuilding parity. That doesn't erase the data disks, so you could put the drive back, just not simply.

 

Upgrading by rebuilding and keeping the old disks intact is a good way to start on a full backup, as the replaced drives will still have all the data on them that was there when they were upgraded.