Btrfs is a great filesystem, but its userland tools are not very user-friendly yet.
As a long-time user, I've developed btrfs-list as a wrapper to make sense out of the btrfs sub list and btrfs qgroup show commands.
You need btrfs-list if either:
- You'd like to have a nice tree-style overview of your subvolumes/snapshots
- You've already used ZFS before and you're missing the zfs list command
- You're looking for exactly which snapshot to destroy to regain some space
- You're using
btrfs-progs< v5.7 and you're looking for a more accurate estimation of how much space is remaining on your FS for all btrfs supported data profiles, as corner cases of raid1/raid10 are not handled well by older versions ofbtrfs-progs, and raid5/raid6 were not implemented at all
Basically it turns this:
into this:
btrfs-progsv3.18 at least (Dec 2014)- The quota feature enabled on your Btrfs filesystems (optional, to get space usage for subvolumes and snapshots)
Usage: btrfs-list [options] [mountpoint1 [mountpoint2 [...]]]
If no mountpoints are specified, display info for all btrfs filesystems.
-h, --help display this message
--debug enable debug output
-q, --quiet silence quota disabled & quota rescan warnings,
repeat to silence all other warnings.
--version display version info
--color WHEN colorize the output; WHEN can be 'never',
'always', or 'auto' (default is:
colorize if STDOUT is a term)
-n, --no-color synonym of --color=never
--bright use bright colors (better for dark terminals)
-H, --no-header hide header from output
-r, --raw show raw numbers instead of human-readable
--btrfs-binary BIN path to the btrfs binary to use instead of using
the first binary found in the PATH
--ignore-version-check try to continue even if btrfs-progs seems too old
--ignore-root-check try to continue even if we are not root
-s, --hide-snap hide all snapshots
-S, --snap-only only show snapshots
-d, --deleted show deleted parents of orphaned snapshots
--snap-min-excl SIZE hide snapshots whose exclusively allocated extents
take up less space than SIZE
--snap-max-excl SIZE hide snapshots whose exclusively allocated extents
take up more space than SIZE
-f, --free-space only show free space on the filesystem
-u, --used display used space instead of free space
-p, --profile PROFILE override data profile detection and consider it
as 'dup', 'single', 'raid0', 'raid1',
'raid1c3', 'raid1c4', 'raid10', 'raid5' or
'raid6' for free space calculation
-a, --show-all show all information for each item
--show-gen show generation of each item
--show-cgen show generation at creation of each item
--show-id show id of each item
--show-parent show parent id of each item
--show-toplevel show top level of each item
--show-uuid show uuid of each item
--show-puuid show parent uuid of each item
--show-ruuid show received uuid of each item
--show-otime show snap creation time
-w, --wide don't truncate uuids on output (this is the
default if STDOUT is NOT a term)
--no-wide always truncate uuids on output (useful to
override above default)
--max-name-len LEN trim long subvol names to LEN. 0 means never trim.
Defaults to 80 if STDOUT is a term, 0 otherwise.
--indent LEN number of spaces to indent the tree, default: 3.
SIZE can be a number (in bytes), or a number followed by k, M, G, T or P.
root@nas:~# btrfs-list /git
NAME TYPE REFER EXCL MOUNTPOINT
git fs - 58.96G (single, 17.27G free)
[main] mainvol 60.61G 292.00k /git
.beeshome subvol 56.64M 56.64M
.snaps/20220103_005415_daily.0 rosnap 60.54G 144.00k
.snaps/20220101_004815_daily.2 rosnap 60.42G 160.00k
.snaps/20211229_004815_daily.5 rosnap 60.42G 160.00k
.snaps/20220102_005203_daily.1 rosnap 60.42G 160.00k
.snaps/20220103_114214_hourly.6 rosnap 60.54G 144.00k
.snaps/20220103_154814_hourly.2 rosnap 60.61G 144.00k
.snaps/20220103_175114_hourly.0 rosnap 60.61G 144.00k
.snaps/20211230_004815_daily.4 rosnap 60.42G 160.00k
.snaps/20211231_004815_daily.3 rosnap 60.42G 160.00k
.snaps/20220103_144814_hourly.3 rosnap 60.61G 144.00k
.snaps/20220103_164815_hourly.1 rosnap 60.61G 144.00k
.snaps/20220103_124215_hourly.5 rosnap 60.54G 2.23M
.snaps/20220103_134556_hourly.4 rosnap 60.60G 480.00k
.snaps/20220103_104215_hourly.7 rosnap 60.54G 144.00k
root@nas:/mnt/b# btrfs-list -qad .
NAME ID PARENT TOPLVL GEN CGEN UUID PARENTUUID RCVD_UUID OTIME TYPE EXCL MOUNTPOINT
7cb8325f - - - - - - - - - fs 157.00M (raid5, 3.59G free, 2.74G unallocatable)
[main] 5 - - - - - - - - mainvol - /mnt/b
sub1 258 5 5 21 8 ae9c..6cae - - - subvol -
sub1/.snap1 259 258 258 9 9 2d50..2094 ae9c..6cae - 2022-01-03 18:39:48 snap -
sub1/.snap2 260 258 258 10 10 a2e9..1431 ae9c..6cae - 2022-01-03 18:39:48 snap -
sub1/.snap3 270 258 258 20 20 b054..6ce2 ae9c..6cae - 2022-01-03 18:41:26 snap -
sub1/.snap4 271 258 258 21 21 ae07..cc69 ae9c..6cae - 2022-01-03 18:41:27 snap -
sub1/subsub1 261 258 258 14 11 bdf1..e7fe - - - subvol -
sub1/subsub1/.snapA1 262 261 261 12 12 ab9b..e6df bdf1..e7fe - 2022-01-03 18:40:09 snap -
sub1/subsub1/.snapA2 263 261 261 13 13 407c..1a14 bdf1..e7fe - 2022-01-03 18:40:09 snap -
sub2 265 5 5 19 15 bc35..8104 - - - subvol -
sub3 266 5 5 17 16 eb52..da06 - - - subvol -
sub3/subsub3 267 266 266 32 17 eb81..00af - - - subvol -
sub3-snaps/.snapK 280 279 279 30 30 41b9..442a eb81..00af - 2022-01-03 18:43:25 snap -
sub3-snaps/.snapL 281 279 279 31 31 3308..f953 eb81..00af - 2022-01-03 18:43:25 snap -
sub2/subsub2 268 265 265 28 18 2189..08b4 - - - subvol -
sub2/subsub2/.snapB 269 268 268 19 19 259d..0afd 2189..08b4 - 2022-01-03 18:41:15 snap -
sub2/subsub2/.snapC 272 268 268 24 22 8ae4..1313 2189..08b4 - 2022-01-03 18:41:49 snap -
sub2/subsub2/.snapB-backup 294 268 268 24 24 fe27..2169 259d..0afd - 2022-01-03 18:42:05 snap -
sub2/subsub2/.snapC-backup 274 268 268 24 24 da86..1964 8ae4..1313 - 2022-01-03 18:42:03 snap -
sub2/subsub2/.snapD 273 268 268 23 23 713f..6a28 2189..08b4 - 2022-01-03 18:41:50 snap -
sub2-snaps/.snapX 276 275 275 26 26 97ef..7187 2189..08b4 - 2022-01-03 18:43:04 snap -
sub2-snaps/.snapZ 278 275 275 28 28 4c08..f7fb 2189..08b4 - 2022-01-03 18:43:06 snap -
sub2-snaps 275 5 5 28 25 3ce4..2ae3 - - - subvol -
sub3-snaps 279 5 5 32 29 05c9..0620 - - - subvol -
sub4-snaps 284 5 5 37 34 2366..b451 - - - subvol -
(deleted) - - - - - 05eb..d578 - - - deleted -
sub4-snaps/sub4-bkp1 285 284 284 35 35 0134..77cb 05eb..d578 - 2022-01-03 18:45:11 snap -
sub4-snaps/sub4-bkp2 286 284 284 36 36 587b..e3e0 05eb..d578 - 2022-01-03 18:45:11 snap -
sub4-snaps/sub4-bkp3 287 284 284 37 37 55eb..e32e 05eb..d578 - 2022-01-03 18:45:12 snap -
Note that the hierarchy here is the hierarchy between the subvolumes and snapshots, not the folder hierarchy.
This is why for example sub3-snaps/.snapK is under sub3/subsub3, because it is a snapshot of this subvolume,
even if in the folder hierarchy, it is under sub3-snaps.
Same goes for .snapD and .snapX, these are at a different spot in the folder hierarchy, but both are snapshots
of the sub2/subsub2 subvolume, hence are placed under it.
We also have 3 snapshots of a (deleted) subvolume, these ghosts subvolumes are shown with the option -d.
root@nas:/tmp/md5# btrfs-list -f
NAME TYPE EXCL MOUNTPOINT
var fs 18.09G (single, 5.62G free)
root fs 950.39M (single, 36.61M free)
newtank fs 15.61T (raid1, 764.30G free)
git fs 58.96G (single, 17.27G free)
opt fs 1.11G (single, 668.23M free)
incoming fs 26.18T (single, 1.07T free)
7cb8325f fs 157.00M (raid5, 3.59G free, 2.74G unallocatable)
home fs 13.64G (single, 5.99G free)
slash fs 19.80G (single, 11.70G free)
varlog fs 12.26G (single, 3.96G free)
root@nas:~# btrfs-list --snap-min-excl 4G --snap-only /tank
NAME TYPE REFER EXCL MOUNTPOINT
backups/.snaps/skyline/20130213_231649_lastskyline rosnap 22.52G 19.58G
backups/.snaps/box/20171231_221207_monthly.12 rosnap 88.73G 4.96G
backups/.snaps/box/20180130_221209_monthly.11 rosnap 91.25G 4.90G
backups/.snaps/box/20180307_154215_monthly.10 rosnap 96.28G 10.72G
backups/.snaps/box/20190120_193004_weekly.3 rosnap 56.45G 4.25G
backups/.snaps/nasroot/20180122_091325_monthly.12 rosnap 34.65G 10.79G
backups/.snaps/nasroot/20180221_092311_monthly.11 rosnap 31.96G 4.98G
backups/.snaps/nasroot/20180323_092734_monthly.10 rosnap 33.69G 7.05G
backups/.snaps/nasroot/20180820_205559_monthly.5 rosnap 31.74G 5.37G
.syncthing-bkp rosnap 40.48G 8.15G
Note: this is fixed with recent versions of btrfs-progs (v5.7 onwards), but we'll keep this feature to continue
supporting older releases of btrfs-progs if for some reason you're stuck with older versions.
For RAID5/6 setups, old versions of btrfs filesystem usage always display 0 bytes in the Free (estimated) section,
and you have no way to know the free space of your filesystem. btrfs-list handles this transparently by doing
the calculations needed to report the proper amount of free space, even in RAID5/6 setups.