File System Explanation

[jtcweb]

I have repeatedly looked and cannot find an explanation on the different file systems and why I should select one over another.  Also what is the process to convert a drive?  I currently have a cache drive that is btrfs, three data drives that are reiserfs and one data drive that is xfs.  Is there a problem with having drives with mixed file systems?

Edited November 14, 2017 by jtcweb

[ashman70]

Not that I am aware of, however it is not considered best practice. ReiserFS is a dead file system and has issues when drives get full so there is no reason to stay on ReiserFS, you should just migrate all your drives to XFS. BTRFS has it's merits specifically on unRAID as opposed to hardware RAID, and there is quite a bit of info about it out there, but for most people I would think XFS should suffice.

[Frank1940]

50 minutes ago, jtcweb said:

Also what is the process to convert a drive?

See here:

 

     https://forums.lime-technology.com/topic/54769-format-xfs-on-replacement-drive-convert-from-rfs-to-xfs/

 

I would suggest getting away from reiserfs because its development ceased about 2009 when its developer was convicted of murdering his wife and sentenced to life-in-prison.  (Remember how much drive capacity has increased since 2009 and the  reiserfs has had issues as these large capacity drives become full.)   The less data you have on your array, the quicker the changeover will go.  Waiting will only make the conversion an even longer process.

 

[jtcweb]

I tried following the instructions listed above and was not able to.  I'm able to empty the drive (I use mc in a terminal window) but I cannot figure out how to reformat the drive.  Can anyone tell me how to:

1. remove an empty drive form the pool without needing to re-do the parity drive.
2. How do I format the drive in xfs?  The only way I could figure out how was to pre-clear the drive.

[Frank1940]

5 minutes ago, jtcweb said:

remove an empty drive form the pool without needing to re-do the parity drive.

 

You can't.  Even if the drive is empty it still is formatted and that formatting information is a part of parity.

 

6 minutes ago, jtcweb said:

How do I format the drive in xfs?  The only way I could figure out how was to pre-clear the drive.

 

You could do this:

        https://wiki.lime-technology.com/UnRAID_6_2/Storage_Management#Removing_disks

 

However, I would suggest that you carefully reread the instructions in the link in the earlier that I provided you.  The drive you just emptied is the the 'Swap Drive' and start with Step 4 of the procedure.  When I did the conversion procedure, I first printed out the procedure so I could have it at hand and highlighted the places where I might get confused.  I set up a step-by-step table and check list with the disk numbers for each disk so that I didn't get confused.   The process is a bit intimidating and, if you are like most of us, you will be confused on first reading it.  Read through it a couple of times and set it aside for a few hours and study it again.  

 

 

[trurl]

You should not be removing the drives. Removing a drive requires rebuilding parity. Formatting a drive while it is in the array preserves parity, since format is a write operation and unRAID updates parity any time an array disk is written. All format does (and all it means) is writing an empty root folder to the disk.

 

To format a disk in the array after you have emptied it, stop the array, click on the drive to get to its settings page, and change its filesystem. unRAID will format the drive to the new filesystem when you start the array.