Replace data drive without rebuild

[SnarfsMojo]

Good evening, i'm hoping someone can help me out -

 

I am replacing qty8 4tb drives with qty 8 8tb drives.  I have enough room in my array to add the 8tb drives in alongside the existing 4tb drives.

 

I would like to use unbalance to move the data off of the 4tb drives and onto the 8tb drives.

Once the 4tb drives have been emptied, could I just remove them from the array (stop array, physically remove the drives, start the array).

 

My main concern is how much trashing removing the 4tb drives using the standard procedure (rebuilding the drive from parity plus the data on the existing drives) will cause.

 

I have already migrated about 50% of one of the 4tb drives to an 8tb drive, then started doing some digging and realizing it may not be the best approach.

 

TIA for anyone who can help

 

Snarfy

[trurl]

1 minute ago, SnarfsMojo said:

Once the 4tb drives have been emptied, could I just remove them from the array (stop array, physically remove the drives, start the array

You could New Config without them and rebuild parity.

[trurl]

Probably simpler, less error-prone, and maybe not much more disk activity, to just rebuild each onto the larger disk.

 

Your plan will move files to larger disks, which involves writing the new disk and updating parity, plus deleting from the source disk and updating parity.

 

Plus rebuild means you will still have the original disks with their contents in case of problems, or even as backups.

[trurl]

Just now, trurl said:

Your plan will move files to larger disks, which involves writing the new disk and updating parity, plus deleting from the source disk and updating parity.

And you would still have to rebuild parity to get those empty disks out of the array.

[SnarfsMojo]

Thanks for the prompt replies!

Is there a need to check parity after every rebuild (pulling a 4tb drive, replacing it with an 8tb drive, letting the 8tb drive rebuild based on parity settings)?

[JonathanM]

13 minutes ago, SnarfsMojo said:

Is there a need to check parity after every rebuild

If the rebuild completed with no errors, it should be fine. However...

Since the rebuild writes to the new drive without verifying that the data can be successfully read, it's possible that the next rebuild could run into errors and fail.

 

So, not necessary, but probably a good idea.

 

Non-correcting parity check is a good way to determine if a subsequent rebuild will be successful.