Thanks very much for the reply, Hans. I'm just responding to your note about mout options here.
On 16/09/18, Hans van Kranenburg ([email protected]) wrote: > > The machine is btrfs-progs v4.7.3 Linux 4.9.0-8-amd64 on Debian. The > > coreutils version is 8.26-3. > > Another note: since it seems you have about 100% more data space > allocated (set apart for data purpose) than you're actually using, or in > other words, having the 1GiB chunks on average just for 50% filled... > > Data, RAID1: total=2.52TiB, used=1.36TiB > > ...in combination with using Linux 4.9, I suspect there's also 'ssd' in > your mount options (not in fstab, but enabled by btrfs while mounting, > see /proc/mounts or mount command output)? > > If so, this is a nice starting point for more info about what might also > be happening to your filesystem: > https://www.spinics.net/lists/linux-btrfs/msg70622.html My mount options are (according to 'mount'): /dev/mapper/cdisk2 on /bkp type btrfs (rw,noatime,compress=lzo,space_cache,subvolid=5,subvol=/) Perhaps I need to run a balance, as suggested in your message recorded on spinics? mount doesn't report the ssd option though, as you suggest it might. Perhaps the compression flag is the culprit here. Many thanks Rory
