How to prevent data loss or corruption when unmounting?

To avoid losing or damaging data, follow these suggestions when unmounting a filesystem using the umount command.

1. Make sure no programs are accessing the unmounted file system. You can use the lsof command to see which processes are using the file system and then terminate them.
2. Use the sync command to write all data to the disk, ensuring that all data has been written to the disk rather than being stored in the cache.
3. Before executing the umount command, make sure the file system is not mounted elsewhere. You can use the mount command to check the current mounting status of the file system.
4. It is advisable to avoid sudden power outages or system restarts during the execution of the umount command, as this may result in data loss or corruption. It is best to backup data before running the umount command.
5. You can add the “-l” option in the umount command to force unmount the file system, even if there are files or directories still in use on the file system.

Following the above advice can help reduce the risk of data loss or damage.