Btrfs assistant "internal filesystem statistics" data utilization 90% full, despite few snapshots

bluedashes · June 21, 2025, 10:14pm

Hello! First just wanted to say that my primary reason for using Garuda is excellent implementation of luks w btrfs + snapper right out of the box. Automatic snapshots when updates occur, and easy rollback!! : )

However - I have been using it for a few weeks, and though imho there’s not much on this single 512gb nvme disk, btrfs assistant data utilization says it is staying above 90%, even though I have manually deleted most of the snapshots (8 remain), manually ran the maintenance (scrub + balance), refreshed, & rebooted a few times.

I haven’t changed the default from the 20 snaps it is supposed to keep. The timeline is disabled. I had a few manual snapshots but I deleted those as well.

Otherwise my Garuda Cinnamon install is working great. Also, it is solely Garuda, no multiboot.

I tried using google search technique to hit the arch linux forum, but could not find any hits re: the “internal filesystem statistics”. Also nothing on this particular issue in the arch wiki.

No specific topic mentioning this in the Garuda forum.

Thanks.

System:
  Kernel: 6.15.2-zen1-1-zen arch: x86_64 bits: 64 compiler: gcc v: 15.1.1
    clocksource: tsc avail: acpi_pm
    parameters: BOOT_IMAGE=/@/boot/vmlinuz-linux-zen
    root=UUID=bdbe16b2-ceee-4f81-a205-210bcdf361a1 rw rootflags=subvol=@
    quiet rd.luks.uuid=edf8296a-6adb-44c6-bd06-94560ab77668 loglevel=3
    ibt=off
  Desktop: Cinnamon v: 6.4.10 tk: GTK v: 3.24.49 wm: Muffin v: 6.4.1 tools:
    avail: cinnamon-screensaver,xautolock vt: 7 dm: LightDM v: 1.32.0
    Distro: Garuda base: Arch Linux
Machine:
  Type: Laptop System: Dell product: Latitude 7390 v: N/A
    serial: <superuser required> Chassis: type: 10 serial: <superuser required>
  Mobo: Dell model: N/A serial: <superuser required> part-nu: 081B
    uuid: <superuser required> UEFI: Dell v: 1.43.0 date: 03/06/2025
Battery:
  ID-1: BAT0 charge: 43.1 Wh (87.6%) condition: 49.2/60.0 Wh (82.0%)
    volts: 8.3 min: 7.6 model: BYD DELL KG7VF1C type: Li-poly serial: <filter>
    status: discharging
CPU:
  Info: model: Intel Core i7-8650U bits: 64 type: MT MCP arch: Coffee Lake
    gen: core 8 level: v3 note: check built: 2017 process: Intel 14nm family: 6
    model-id: 0x8E (142) stepping: 0xA (10) microcode: 0xF6
  Topology: cpus: 1x dies: 1 clusters: 4 cores: 4 threads: 8 tpc: 2
    smt: enabled cache: L1: 256 KiB desc: d-4x32 KiB; i-4x32 KiB L2: 1024 KiB
    desc: 4x256 KiB L3: 8 MiB desc: 1x8 MiB
  Speed (MHz): avg: 400 min/max: 400/4200 scaling: driver: intel_pstate
    governor: powersave cores: 1: 400 2: 400 3: 400 4: 400 5: 400 6: 400 7: 400
    8: 400 bogomips: 33599
  Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx
  Vulnerabilities: <filter>
Graphics:
  Device-1: Intel UHD Graphics 620 vendor: Dell driver: i915 v: kernel
    arch: Gen-9.5 process: Intel 14nm built: 2016-20 ports: active: eDP-1
    empty: DP-1, DP-2, HDMI-A-1, HDMI-A-2 bus-ID: 00:02.0 chip-ID: 8086:5917
    class-ID: 0300
  Device-2: Realtek Integrated_Webcam_HD driver: uvcvideo type: USB rev: 2.1
    speed: 480 Mb/s lanes: 1 mode: 2.0 bus-ID: 1-5:2 chip-ID: 0bda:58ca
    class-ID: 0e02 serial: <filter>
  Display: x11 server: X.Org v: 21.1.18 with: Xwayland v: 24.1.8 driver: X:
    loaded: modesetting alternate: fbdev,intel,vesa dri: iris gpu: i915
    display-ID: :0 screens: 1
  Screen-1: 0 s-res: 1280x720 s-dpi: 96 s-size: 339x191mm (13.35x7.52")
    s-diag: 389mm (15.32")
  Monitor-1: eDP-1 model: ChiMei InnoLux 0x1382 built: 2017 res:
    mode: 1280x720 hz: 60 scale: 100% (1) dpi: 111 gamma: 1.2
    size: 293x165mm (11.54x6.5") diag: 336mm (13.2") ratio: 16:9
    modes: 1920x1080
  API: EGL v: 1.5 hw: drv: intel iris platforms: device: 0 drv: iris
    device: 1 drv: swrast gbm: drv: iris surfaceless: drv: iris x11: drv: iris
    inactive: wayland
  API: OpenGL v: 4.6 compat-v: 4.5 vendor: intel mesa v: 25.1.4-arch1.1
    glx-v: 1.4 direct-render: yes renderer: Mesa Intel UHD Graphics 620 (KBL
    GT2) device-ID: 8086:5917 memory: 30.48 GiB unified: yes
  API: Vulkan v: 1.4.313 layers: 5 device: 0 type: integrated-gpu name: Intel
    UHD Graphics 620 (KBL GT2) driver: mesa intel v: 25.1.4-arch1.1
    device-ID: 8086:5917 surfaces: N/A device: 1 type: cpu name: llvmpipe
    (LLVM 20.1.6 256 bits) driver: mesa llvmpipe v: 25.1.4-arch1.1 (LLVM
    20.1.6) device-ID: 10005:0000 surfaces: N/A
  Info: Tools: api: eglinfo, glxinfo, vulkaninfo
    x11: xdpyinfo, xprop, xrandr
Audio:
  Device-1: Intel Sunrise Point-LP HD Audio vendor: Dell driver: snd_hda_intel
    v: kernel alternate: snd_soc_avs bus-ID: 00:1f.3 chip-ID: 8086:9d71
    class-ID: 0403
  API: ALSA v: k6.15.2-zen1-1-zen status: kernel-api
    tools: alsactl,alsamixer,amixer
  Server-1: PipeWire v: 1.4.5 status: active with: 1: pipewire-pulse
    status: active 2: wireplumber status: active 3: pipewire-alsa type: plugin
    4: pw-jack type: plugin tools: pactl,pw-cat,pw-cli,wpctl
Network:
  Device-1: Intel Ethernet I219-LM vendor: Dell driver: e1000e v: kernel
    port: N/A bus-ID: 00:1f.6 chip-ID: 8086:15d7 class-ID: 0200
  IF: enp0s31f6 state: down mac: <filter>
  Device-2: Intel Wireless 8265 / 8275 driver: iwlwifi v: kernel pcie:
    gen: 1 speed: 2.5 GT/s lanes: 1 bus-ID: 02:00.0 chip-ID: 8086:24fd
    class-ID: 0280
  IF: wlp2s0 state: up mac: <filter>
  IF-ID-1: ipv6leakintrf0 state: unknown speed: N/A duplex: N/A
    mac: <filter>
  IF-ID-2: proton0 state: unknown speed: N/A duplex: N/A mac: N/A
  Info: services: NetworkManager, systemd-timesyncd, wpa_supplicant
Bluetooth:
  Device-1: Intel Bluetooth wireless interface driver: btusb v: 0.8 type: USB
    rev: 2.0 speed: 12 Mb/s lanes: 1 mode: 1.1 bus-ID: 1-7:3 chip-ID: 8087:0a2b
    class-ID: e001
  Report: btmgmt ID: hci0 rfk-id: 2 state: up address: N/A
Drives:
  Local Storage: total: 832.58 GiB used: 41.66 GiB (5.0%)
  SMART Message: Required tool smartctl not installed. Check --recommends
  ID-1: /dev/mmcblk0 maj-min: 179:0 vendor: SanDisk model: SC400
    size: 366.82 GiB block-size: physical: 512 B logical: 512 B type: Removable
    tech: SSD serial: <filter> scheme: MBR
  ID-2: /dev/nvme0n1 maj-min: 259:0 vendor: Crucial model: CT500P3PSSD8
    size: 465.76 GiB block-size: physical: 512 B logical: 512 B speed: 63.2 Gb/s
    lanes: 4 tech: SSD serial: <filter> fw-rev: P9CR40D temp: 33.9 C
    scheme: GPT
Partition:
  ID-1: / raw-size: 465.46 GiB size: 465.46 GiB (100.00%)
    used: 17.69 GiB (3.8%) fs: btrfs dev: /dev/dm-0 maj-min: 253:0
    mapped: luks-edf8296a-6adb-44c6-bd06-94560ab77668
  ID-2: /boot/efi raw-size: 300 MiB size: 299.4 MiB (99.80%)
    used: 776 KiB (0.3%) fs: vfat dev: /dev/nvme0n1p1 maj-min: 259:1
  ID-3: /home raw-size: 465.46 GiB size: 465.46 GiB (100.00%)
    used: 17.69 GiB (3.8%) fs: btrfs dev: /dev/dm-0 maj-min: 253:0
    mapped: luks-edf8296a-6adb-44c6-bd06-94560ab77668
  ID-4: /var/log raw-size: 465.46 GiB size: 465.46 GiB (100.00%)
    used: 17.69 GiB (3.8%) fs: btrfs dev: /dev/dm-0 maj-min: 253:0
    mapped: luks-edf8296a-6adb-44c6-bd06-94560ab77668
  ID-5: /var/tmp raw-size: 465.46 GiB size: 465.46 GiB (100.00%)
    used: 17.69 GiB (3.8%) fs: btrfs dev: /dev/dm-0 maj-min: 253:0
    mapped: luks-edf8296a-6adb-44c6-bd06-94560ab77668
Swap:
  Kernel: swappiness: 133 (default 60) cache-pressure: 100 (default) zswap: no
  ID-1: swap-1 type: zram size: 31.21 GiB used: 0 KiB (0.0%) priority: 100
    comp: zstd avail: lzo-rle,lzo,lz4,lz4hc,deflate,842 dev: /dev/zram0
Sensors:
  System Temperatures: cpu: 49.0 C pch: 44.0 C mobo: N/A
  Fan Speeds (rpm): N/A
Info:
  Memory: total: 32 GiB available: 31.21 GiB used: 3.07 GiB (9.8%)
  Processes: 286 Power: uptime: 13m states: freeze,mem,disk suspend: deep
    avail: s2idle wakeups: 0 hibernate: platform avail: shutdown, reboot,
    suspend, test_resume image: 12.46 GiB services: csd-power,upowerd
    Init: systemd v: 257 default: graphical tool: systemctl
  Packages: pm: pacman pkgs: 1405 libs: 417 tools: gnome-software, octopi,
    pamac, paru, yay Compilers: gcc: 15.1.1 Shell: garuda-inxi default: Bash
    v: 5.2.37 running-in: gnome-terminal inxi: 3.3.38
Garuda (2.7.2-1):
  System install date:     2025-06-07
  Last full system update: 2025-06-21
  Is partially upgraded:   No
  Relevant software:       snapper NetworkManager dracut
  Windows dual boot:       Probably (Run as root to verify)
  Failed units:

BluishHumility · June 21, 2025, 11:06pm

These metrics in the overview are not indicating how much of the disk or filesystem are in use, but rather how much of the total space occupied by that block group type is in use. See the explanation in the btrfs-filesystem man page here (under usage): btrfs-filesystem(8) — BTRFS documentation

The root user will also see stats broken down by block group types:
Data,single: Size:1.15TiB, Used:1.13TiB (98.26%)
   /dev/sdb        1.15TiB

Metadata,single: Size:12.00GiB, Used:6.45GiB (53.75%)
   /dev/sdb       12.00GiB

System,single: Size:32.00MiB, Used:144.00KiB (0.44%)
   /dev/sdb       32.00MiB

Unallocated:
   /dev/sdb      669.99GiB
Data is block group type, single is block group profile, Size is total size occupied by this type, Used is the actually used space, the percent is ratio of Used/Size. The Unallocated is remaining space.

See also the relevant section of the Btrfs Assistant wiki:

If you want to see how much disk space is available, check what it says next to “Free”.

bluedashes · June 21, 2025, 11:49pm

Thank you for your super fast reply! Ok then my question is: is a high percentage here something to be concerned about? If so, how do i clear it up? Maybe i’m just missing something blatantly obvious here.

BluishHumility · June 22, 2025, 12:44am

No, you shouldn’t worry about the high usage percentages shown in the block groups as long as you have plenty of unallocated space. Your disk is nearly empty, by the way:

So you should be totally fine.

Btrfs will dynamically allocate more space to each category as needed. If the data block group becomes full, Btrfs can automatically grow it.

The numbers in this section are mostly for keeping an eye on space pressure or fragmentation issues. If usage in a block group hits 100% and space cannot be allocated for some reason (for example, due to fragmentation or quotas), then you might need to run a balance on the disk (to redistribute chunks across the filesystem and reclaim space from the less utilized block groups).

bluedashes · June 22, 2025, 3:43pm

Thanks so much! I knew the disk was mostly empty via various tools, and I don’t anticipate storing much more on there. But am unfamiliar with block group space and will read up on it.

system · June 24, 2025, 3:43pm

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