root@filer1:/# time mkfs.btrfs -L data -d raid6 -m raid1c3 -f /dev/sda /dev/sdb /dev/sdc /dev/sdd /dev/sde btrfs-progs v5.10.1 See http://btrfs.wiki.kernel.org for more information. Label: data UUID: 2c1a5edc-a624-49a4-8a54-222c61d54386 Node size: 16384 Sector size: 4096 Filesystem size: 54.57TiB Block group profiles: Data: RAID6 3.00GiB Metadata: RAID1C3 1.00GiB System: RAID1C3 8.00MiB SSD detected: no Incompat features: extref, raid56, skinny-metadata, raid1c34 Runtime features: Checksum: crc32c Number of devices: 5 Devices: ID SIZE PATH 1 10.91TiB /dev/sda 2 10.91TiB /dev/sdb 3 10.91TiB /dev/sdc 4 10.91TiB /dev/sdd 5 10.91TiB /dev/sde real 0m2.414s user 0m0.001s sys 0m0.129s root@filer1:/# [user01@home pool]$ sudo btrfs subvolume list /pool/sata_hdd_1 ID 256 gen 13 top level 5 path archive [user01@home pool]$ df -h -t btrfs Filesystem Size Used Avail Use% Mounted on /dev/dm-0 462G 4.0G 457G 1% / /dev/dm-0 462G 4.0G 457G 1% /.snapshots /dev/dm-0 462G 4.0G 457G 1% /home /dev/dm-0 462G 4.0G 457G 1% /var/log /dev/dm-0 462G 4.0G 457G 1% /home/.snapshots /dev/dm-1 9.1T 3.9M 9.1T 1% /pool/sata_hdd_1 /dev/dm-1 9.1T 3.9M 9.1T 1% /vol/archive [user01@home pool]$ sudo ls -lha /vol/archive/ total 0 drwxr-xr-x. 1 root root 38 Mar 2 16:29 . drwxr-xr-x. 1 root root 14 Mar 2 16:26 .. -rw-r--r--. 1 root root 0 Mar 2 16:28 Test01_file_vol.txt [user01@home pool]$ sudo ls -lha /pool/sata_hdd_1/archive/ total 16K drwxr-xr-x. 1 root root 38 Mar 2 16:29 . drwxr-xr-x. 1 root root 14 Mar 2 00:53 .. -rw-r--r--. 1 root root 0 Mar 2 16:28 Test01_file_vol.txt ------------------------ # df -h -t btrfs Filesystem Size Used Avail Use% Mounted on /dev/sda 55T 13T 21T 37% /srv/dev-disk-by-uuid-2c1a5edc-a624-49a4-8a54-222c61d54386 # btrfs fi show Label: 'data' uuid: 2c1a5edc-a624-49a4-8a54-222c61d54386 Total devices 5 FS bytes used 11.97TiB devid 1 size 10.91TiB used 4.01TiB path /dev/sda devid 2 size 10.91TiB used 4.01TiB path /dev/sdb devid 3 size 10.91TiB used 4.01TiB path /dev/sdc devid 4 size 10.91TiB used 4.01TiB path /dev/sdd devid 5 size 10.91TiB used 4.01TiB path /dev/sde # btrfs device stats /srv/dev-disk-by-uuid-2c1a5edc-a624-49a4-8a54-222c61d54386/ [/dev/sda].write_io_errs 0 [/dev/sda].read_io_errs 0 [/dev/sda].flush_io_errs 0 [/dev/sda].corruption_errs 0 [/dev/sda].generation_errs 0 [/dev/sdb].write_io_errs 0 [/dev/sdb].read_io_errs 0 [/dev/sdb].flush_io_errs 0 [/dev/sdb].corruption_errs 0 [/dev/sdb].generation_errs 0 [/dev/sdc].write_io_errs 0 [/dev/sdc].read_io_errs 0 [/dev/sdc].flush_io_errs 0 [/dev/sdc].corruption_errs 0 [/dev/sdc].generation_errs 0 [/dev/sdd].write_io_errs 0 [/dev/sdd].read_io_errs 0 [/dev/sdd].flush_io_errs 0 [/dev/sdd].corruption_errs 0 [/dev/sdd].generation_errs 0 [/dev/sde].write_io_errs 0 [/dev/sde].read_io_errs 0 [/dev/sde].flush_io_errs 0 [/dev/sde].corruption_errs 0 [/dev/sde].generation_errs 0 # btrfs filesystem df /srv/dev-disk-by-uuid-2c1a5edc-a624-49a4-8a54-222c61d54386/ Data, RAID6: total=12.00TiB, used=11.95TiB System, RAID1C3: total=8.00MiB, used=976.00KiB Metadata, RAID1C3: total=19.00GiB, used=17.90GiB GlobalReserve, single: total=512.00MiB, used=0.00B # btrfs scrub status /srv/dev-disk-by-uuid-2c1a5edc-a624-49a4-8a54-222c61d54386/ UUID: 2c1a5edc-a624-49a4-8a54-222c61d54386 Scrub started: Tue May 9 08:23:23 2023 Status: finished Duration: 121:07:41 Total to scrub: 12.00TiB Rate: 28.85MiB/s Error summary: no errors found