Status to make btsfs to the standard filesystem of Fedora

[Chris Murphy]

On Jan 24, 2013, at 9:30 PM, Chris Murphy <lists at colorremedies.com> wrote:
> 
> 2x 80GB virtual disks, mkfs.btrfs -d raid1 -m raid1:
> 
> # df -h
> Filesystem      Size  Used Avail Use% Mounted on
> /dev/sdb        160G   56K  158G   1% /mnt

Also, copying a 1G file to /mnt, and I end up with:

# df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/sdb        160G  2.0G  150G   2% /mnt

This is consistent as in raid1 mirror, a 1GB file is effectively duplicated and takes up 2GB of the 160GB volume.

The thing I consider a bug, is this:

[root at f18v mnt]# btrfs fi df /mnt
Data, RAID1: total=4.00GB, used=1000.75MB

Because of the RAID1, the amount of chunks allocated for data, raid1 is actually 8GB, and the amount used is actually 2GB. If this volume wasn't a RAID1, copying a 1GB file would give identical results to the above, except the RAID1 wouldn't be there. So we have df being literal, and btrfs fi df itself being secret decoder ringy. Not cool. But I think this is a known area needing improvement.


Chris Murphy