RakuOS update fails with “Not enough free space in /” despite sufficient disk space
Running:
sudo rakuos update
fails with:
Error: applying rpm transaction: Error: Not enough free space in / (need 876.3 MiB, have 0 B available)
disable this check with diskspacecheck=0
The system has plenty of actual disk space available:
/var: 186G total, 36G used, 143G available
However, / is a 73 MB read-only composefs mount and reports 0 B available:
composefs 73M 73M 0 100% /
Some additional observations:
- /usr is mounted as a writable overlay:overlay on /usr type overlay upperdir=/var/lib/rakuos/overlay/upper
- rakuos-overlay-sync.service completes successfully and reports:RakuOS overlay sync: mounting overlay... RakuOS overlay sync: nothing to do. RakuOS overlay sync: done.
- However, rum paths reports:mode: standalone instead of Split mode.
- /var/lib/rakuos/rum-rpmdb does not exist.
- /var/lib/rakuos/overlay-rpmdb-backup/rpmdb.sqlite does exist (~102 MB).
- /var/lib/rakuos/overlay.state contains:"usrOverlay": null
- bootc status --json also reports:"usrOverlay": null
- bootc status shows the system is running:quay.io/rakuos/rakuos-cosmic:latest Version: latest.20260902
sudo rpm-ostree db diff between the rollback and current deployment shows several normal base-image package updates (e.g. OpenSSL, Qt6, Flatpak and VirtualBox guest additions), so the current deployment itself appears to be newer than the rollback.
Suspected issue: the persistent RakuOS /usr overlay is physically mounted, but its overlay state does not appear to be registered with bootc/RUM (usrOverlay: null). As a result, RUM detects the system as standalone rather than Split mode and the update appears to perform an RPM transaction against /, triggering the incorrect disk-space failure on the small read-only composefs.
The system has ~143 GB free on /var, so this does not appear to be an actual disk-space shortage.