The mkfs.s3ql command


mkfs.s3ql [options] <storage url>


The mkfs.s3ql command creates a new file system in the location specified by storage url. The storage url depends on the backend that is used. The S3QL User’s Guide should be consulted for a description of the available backends.

Unless you have specified the --plain option, mkfs.s3ql will ask you to enter an encryption password. This password will not be read from an authentication file specified with the --authfile option to prevent accidental creation of an encrypted file system.


The mkfs.s3ql command accepts the following options.

--cachedir <path>
 Store cached data in this directory (default: ~/.s3ql)
--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). Debug messages will be written to the target specified by the --log option.
--debug Activate debugging output from all S3QL modules. Debug messages will be written to the target specified by the --log option.
--quiet be really quiet
--backend-options <options>
 Backend specific options (separate by commas). See backend documentation for available options.
--version just print program version and exit
--authfile <path>
 Read authentication credentials from this file (default: ~/.s3ql/authinfo2)
-L <name> Filesystem label
--max-obj-size <size>
 Maximum size of storage objects in KiB. Files bigger than this will be spread over multiple objects in the storage backend. Default: 10240 KiB.
--plain Create unencrypted file system.

Exit Codes

mkfs.s3ql may terminate with the following exit codes:

0:Everything went well.
1:An unexpected error occured. This may indicate a bug in the program.
2:Invalid command line argument or configuration file key.
3:Invalid backend option.
11:No such backend.
12:Authentication file has insecure permissions.
13:Unable to parse proxy settings.
14:Invalid credentials (Authentication failed).
15:No permission to access backend (Authorization denied).
16:Invalid storage URL, specified location does not exist in backend.
19:Unable to connect to backend, can’t resolve hostname.
45:Unable to access cache directory.

See Also

The S3QL homepage is at

The full S3QL documentation should also be installed somewhere on your system, common locations are /usr/share/doc/s3ql or /usr/local/doc/s3ql.