Manage Moss States and Packages
Moss keeps track of packaging-related operations that change the state of the /usr directory by creating a new filesystem transaction (fstx) for each associated moss operation, be it package installation, removal or upgrades.
Use the commands below to inspect and manage those states, discover software, and keep your system current.
Check the current state
Section titled “Check the current state”- List the active state to confirm what is running right now.
moss state active- Review the state history when you need context for a rollback.
moss state listUse the state ID (the number after State #) when you need to query or activate a specific snapshot.
Activate a different state
Section titled “Activate a different state”Follow these steps to roll back or advance to another state safely.
- Identify the target state ID with
moss state list. - Activate that state.
sudo moss state activate 128- Verify the change.
moss state activeActivating a state atomically swaps the currently active state’s /usr directory with the new states’s /usr directory, using the Linux kernel renameat2 syscall.
On successful activation of the new state, it is recommended to reboot the system, so that long-running services start with the expected binaries, libraries, and configurations.
Search for packages
Section titled “Search for packages”Use keyword searches to discover software by name or summary.
sudo moss search fractionalAdd --installed (-i) if you only want to search software that is already present on the system.
Search for installed files
Section titled “Search for installed files”Look up which package delivered a specific file when you troubleshoot or audit an installation.
sudo moss search-file libEGL.somoss search-file scans files from installed packages only.
Install software
Section titled “Install software”- Refresh repository metadata when needed.
sudo moss repo update- Install one or more packages.
sudo moss install howdy-gitMoss creates a new state automatically. Confirm success with moss state active.
Update the system
Section titled “Update the system”Keep the entire system current with a sync operation.
sudo moss sync --update--update (-u) pulls fresh repository metadata before applying upgrades. Moss records the result as a new state, so you can roll back if something goes wrong.
Remove software
Section titled “Remove software”Uninstall packages you no longer need.
sudo moss remove howdy-gitMoss snapshots the removal in a new state. Use moss state list to find the previous state if you have to recover.
List currently installed software
Section titled “List currently installed software”moss list installed