Convert RFS to XFS with no spare slots

[RoninTech]

I have read but I think I'm maybe between documented scenarios.  ?

 

I have no spare slots to play with but I have a 1TB drive I'd like to get rid of.  I'm currently using the unbalance plugin to get everything off this 1TB drive.  After that I have a 4TB drive (largest size) I'd like to swap for the 1TB that  I'll use as the starting swap disk for FRS to XFS conversion.

 

1. Monthly parity finished this morning so all is good, dockers disabled so array should be static
2. unbalance everything off the 1TB drive
3. remove the 1TB drive
4. add the 4TB drive formatted as XFS
5. follow the File System Conversion FAQ steps

 

I'm not sure what I need to do for steps 3 and 4 as far as parity checking and Tools->New Config, if anything?  I'm hoping I don't have to do an extra parity check somewhere in there to swap out the 1TB drive.

 

[trurl]

You will have to New Config and rebuild parity to remove a disk. You could also add the 4TB disk with the same New Config and format it to XFS.
 

Even if all the files are deleted from a disk, the filesystem still remains, and it still contains most of the bits of the deleted data. All of those bits are part of parity, so if you remove them parity must be rebuilt. And if you add the 4TB disk with the same New Config, it will be included in the parity build.

 

The alternative is to replace/rebuild the 4TB in place of the 1TB, then reformat it to XFS.

 

If you rebuild the "empty" 1TB disk to the 4TB disk, parity remains valid, and then formatting that 4TB disk to XFS will also update parity so it remains valid.

 

Any write operation immediately updates parity. Delete is a write operation, it writes to the filesystem to mark the file as deleted and its space reusable. And format is a write operation, it writes an empty filesystem, which creates the top level directory ready to have files and folders added to it.

[RoninTech]

Thanks Trurl!  I've never done a new config before.  Once the 1TB disk is empty, do I power down, remove it, replace it with the 4TB, power up, stop the array and then use New Config to format the new 4TB slot to XFS?  Finally rebuild parity so the new empty 4TB XFS drive is covered?  Does that sound right?

 

 

[itimpi]

When you do the New Config select the option to keep the current drive assignments This avoids having to re-Enter the current disk assignments for the drives you are leaving in place).    Then when you go to the Main tab you can change the slot that had the 1TB drive to have the 4TB one instead, and set it to use XFS format..  leave the other disks alone.  You now start the array which will bring the array online and start to build parity.    At this point the new disk will show up as unmountable and there will be an option to format all unmountable disks - you want to make sure that only the new disk is shown there as the format wipes any existing data.   You can do the format while the parity sync is running if you want or you can wait until the end.    Once the format has completed (it should only take a minute or so) the disk is ready for use.    You will want to wait for the sync to complete so the array is back in a protected state before doing any moving of data as any file activity while the parity sync is running is going on slows it down.

[RoninTech]

OK, I didn't see anywhere to change the new 4TB drive to XFS after doing a new config so I started it and now it's doing a parity rebuild and shows the drive as reiserfs.  When the parity is done (assuming I can't stop it?), how do I convert the new empty 4TB drive to XFS?

[itimpi]

8 minutes ago, RoninTech said:

OK, I didn't see anywhere to change the new 4TB drive to XFS after doing a new config so I started it and now it's doing a parity rebuild and shows the drive as reiserfs.  When the parity is done (assuming I can't stop it?), how do I convert the new empty 4TB drive to XFS?

You should have had the option to explicitly set the format if you had clicked on the disk in the Main tab.    The default is ‘auto’ which means leave any existing format alone.  

 

When the parity sync is finished stop the array and click on the disk to change its format.   It is probably currently set to ‘Auto’, but you can set it to explicitly be XFS.   On restarting the array it will be shown as unmountable and the option to format it will be available at the bottom of the Main tab.  Go ahead with the format to make the disk ready for use.

Edited August 26, 2018 by itimpi