To unmount an S3QL file system, use the command:

umount.s3ql [options] <mountpoint>

This will block until all data has been written to the backend.

Only the user who mounted the file system with mount.s3ql is able to unmount it again. If you are root and want to unmount an S3QL file system mounted by an ordinary user, you have to use the fusermount -u or umount command instead. Note that these commands do not block until all data has been uploaded, so if you use them instead of umount.s3ql then you should manually wait for the mount.s3ql process to terminate before shutting down the system.

The umount.s3ql command accepts the following options:

--log <target>

Destination for log messages. Specify none for standard output or syslog for the system logging daemon. Anything else will be interpreted as a file name. Log files will be rotated when they reach 1 MiB, and at most 5 old log files will be kept. Default: None

--debug-modules <modules>

Activate debugging output from specified modules (use commas to separate multiple modules, ‘all’ for everything). Debug messages will be written to the target specified by the --log option.


Activate debugging output from all S3QL modules. Debug messages will be written to the target specified by the --log option.


be really quiet


just print program version and exit

--lazy, -z

Lazy umount. Detaches the file system immediately, even if there are still open files. The data will be uploaded in the background once all open files have been closed.

If, for some reason, the umount.s3ql command does not work, the file system can also be unmounted with fusermount -u -z. Note that this command will return immediately and the file system may continue to upload data in the background for a while longer.