disk-space — Free disk space and inodes¶

Release upgrades download and unpack hundreds of packages under /var and /, and the new release is often bigger than the old one.

At a glance


ID	`disk-space`
Category	Storage
Needs root	no
Needs programs	`df`
Compares with a snapshot	no
Options	6

What it checks¶

Free space and free inodes, as a percentage, on every local filesystem (temporary and virtual ones such as tmpfs, squashfs, overlay and efivarfs are left out). With include_remote: true, network and FUSE filesystems too.
An absolute floor for the important_mounts (/ and /var by default): at least min_free_mib free whatever their size, since a large filesystem can be "only 5% full" and still too full for an upgrade.

Findings¶

Severity	Finding	What to do
critical / warning	Low free space on mount: N% free	Below `critical_pct` / `warning_pct`. Find what uses the space: `sudo du -xh --max-depth=2 MOUNT \| sort -h \| tail`. Common culprits after an upgrade: `sudo apt clean`; `sudo journalctl --vacuum-size=200M`.
critical / warning	Low free inodes on mount: N% free	As above; usually many small files (caches, mail queues).
critical / warning	Only size free on mount	An important mount below `min_free_mib` (critical below half of it).

Commands it runs¶

df -P -T -l -x tmpfs -x devtmpfs -x squashfs -x overlay -x efivarfs
df -P -i -l -x tmpfs -x devtmpfs -x squashfs -x overlay -x efivarfs

With include_remote: true, without -l (local filesystems only):

df -P -T -x tmpfs -x devtmpfs -x squashfs -x overlay -x efivarfs
df -P -i -x tmpfs -x devtmpfs -x squashfs -x overlay -x efivarfs

/boot and the EFI partition have their own check, boot-space.

Limitations¶

Network filesystems are off by default: an unreachable NFS server can make df hang (the command has a timeout).
Filesystems that report no inode counts (btrfs, some network filesystems) are only checked for space.

Options¶

Option	Default	Description
`include_remote`	`false`	Also check network and FUSE filesystems (NFS, CIFS, sshfs, rclone, ...)
`warning_pct`	`25.0`	Warn when free space or inodes drop below this percentage
`critical_pct`	`10.0`	Critical when free space or inodes drop below this percentage
`exclude_mounts`	`[]`	Mount points to leave out (shell-style patterns)
`important_mounts`	`["/", "/var"]`	Mount points that also need min_free_mib free whatever their size; upgrades download and unpack packages here
`min_free_mib`	`2048`	Free space (MiB) the important mounts need: warning below it, critical below half of it; 0 turns this off

Set them in the configuration file under checks: disk-space:, or for one run with --check-option:

checks:
  disk-space:
    enabled: true
    include_remote: false
    warning_pct: 25.0
    critical_pct: 10.0
    exclude_mounts: []
    important_mounts: ["/", "/var"]
    min_free_mib: 2048

pydebuprep report --check-option disk-space.include_remote=false

For a list option, --check-option replaces the configured list; repeat it to give several items.