Replacing Filesystems

[Tophicles]

SO, I've been realizing that I need to convert my RFS to XFS.

The problem is, I have dual parity and no "free" slots on my controllers.

My understanding is the I'll have to break the dual parity anyway (if I'm reading the wiki correctly) so should I un-assign one of my parity drives and use it as the "transfer" slot/drive? For example, un-assign the second parity drive then mount the drive as a "new" data drive and follow the rsync procedure?

Frankly, I'm worried about losing data - not the end of the world, but why rebuild if I don't have to, right?

On the other hand, I do have another controller, should I install it just for the purposes of drive migration? Do I still lose the dual parity?

[JonathanM]

Not sure why you think you must break parity.

 

If you can free up your largest drive by copying the contents elsewhere then formatting it, it's a straightforward rsync source disk to newly formatted destination disk, format source, pick another source drive, continue until done. If you are out of space, yes, you will need another strategy.

 

The only reason you would have to break parity is if you feel you must rearrange disks so the content ends up on the exact same slot as before, and even then you can wait and only break and rebuild parity once after all the copying is done.

 

2 hours ago, Tophicles said:

Frankly, I'm worried about losing data

This is not good. Accidentally losing data either by a botched command line, multiple drive failure, malware, etc, should be an inconvenience, not a show stopper. If you don't have good backups, you need to get that solved BEFORE you play around with the array any further.

 

Parity is not a replacement for backups, it's to keep your array usable while you replace a single failed drive. It doesn't protect against any other threat. Once you have verified proper backups in place, then you no longer need to worry about losing data to whatever comes along.