I've a 18 tera hardware raid 5 (areca ARC-1170 w/ 8 3 gig drives) in need of help. Disk usage (du) shows 13 tera allocated yet strangely enough df shows approx. 780 gigs are free. It seems, somehow, btrfs has eaten roughly 4 tera internally. I've run a scrub and a balance usage=5 with no success, in fact I lost about 20 gigs after the balance attempt. Some numbers: terra:/var/lib/nobody/fs/ubfterra # uname -a Linux terra 3.12.4-2.44-desktop #1 SMP PREEMPT Mon Dec 9 03:14:51 CST 2013 i686 i686 i386 GNU/Linux terra:/var/lib/nobody/fs/ubfterra # parted -l Model: Areca ARC-1170-VOL#00 (scsi) Disk /dev/sdb: 21.0TB Sector size (logical/physical): 4096B/4096B Partition Table: gpt Number Start End Size File system Name Flags 1 1049kB 21.0TB 21.0TB Linux filesystem terra:/var/lib/nobody/fs/ubfterra # du -shc * 1.7M 40588-4-1376856876.jpg 2.7M 40588-4-1376856876b.jpg 1008G Anime 180G Doctor Who (classic) 5.5T Downloads 28G Flash Rescue 1.9T Jus 3.6T Tornado 4.0K dirsanime 4.0K filesanime 55G home videos 0 testsub 4.0K unsharedanime 13T total terra:/var/lib/nobody/fs/ubfterra # btrfs fi show /dev/sdb1 Label: ubfterra uuid: 40f0f692-c68c-4af7-ade2-c15a127ceab5 Total devices 1 FS bytes used 17.61TiB devid 1 size 19.10TiB used 18.34TiB path /dev/sdb1 Btrfs v3.12 terra:/var/lib/nobody/fs/ubfterra # btrfs fi df . Data, single: total=17.58TiB, used=17.57TiB System, DUP: total=8.00MiB, used=1.93MiB System, single: total=4.00MiB, used=0.00 Metadata, DUP: total=392.00GiB, used=33.50GiB Metadata, single: total=8.00MiB, used=0.00 I use no subvolumes nor are there any snapshots, at least as near as I can tell. Any suggestions as to how to recover the missing space assuming it's possible? Any help is most appreciated. -Justin -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html