Filesystem errors

Signs#

• "Read-only file system" when writing — Linux switched the disk to read-only after finding a problem.
• "Input/output error" on files.
• The instance won't start: "the guest kernel panicked while booting".
• Check for disk errors on the Maintenance card finds something.

What to do#

1. Save anything you can — copy important files out to /mnt/mac or with MSL Files.
2. Shut the instance down.
3. Check Disk on the Maintenance card (needs e2fsprogs on your Mac).
4. If it finds problems, Repair Disk…. A backup is taken first.
5. Start the instance and see how it is. If things are worse, Restore… puts the old disk back.
6. When all's well, Discard the backup.

No e2fsprogs? Try the maintenance boot.

Keeping it from happening#

• Shut Linux down properly — sudo poweroff inside it, or msl --shutdown — rather than the app's Shut Down, which stops it at once. See the note on Shut Down.
• Don't restore snapshots after the disk has changed.
• Consider checking at every start.