Managing File Systems

The s3qladm command performs various operations on unmounted S3QL file systems. The file system must not be mounted when using s3qladm or things will go wrong badly.

The syntax is

s3qladm [options] <action> <storage-url>

where action may be either of passphrase, upgrade, clear or download-metadata.

The s3qladm accepts the following general options, no matter what specific action is being invoked:

--authfile <path>
 Read authentication credentials from this file (default: ~/.s3ql/authinfo2)
--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
--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
--backend-options <options>
 Backend specific options (separate by commas). See backend documentation for available options.
--cachedir <path>
 Store cached data in this directory (default: ~/.s3ql)
--version just print program version and exit

Hint: run s3qladm <action> --help to get help on the additional arguments that the different actions take.

Changing the Passphrase

To change the passphrase of a file system, use the passphrase subcommand:

s3qladm passphrase  <storage url>

That this will not actually re-encrypt all the stored data with the new passphrase. Rather, S3QL generates an internal “master key” when the file system is created and uses this key to encrypt all stored data. The user-supplied passphrase is used to encrypt/decrypt only the master key, and can therefore be changed. This means, however, that if a passphrase has been disclosed to someone untrusted, changing it afterwards will not revoke access to people who had access to the old passphrase (because they could have decrypted the master key and retained a copy).

Upgrading the file system

If you have installed a new version of S3QL, it may sometimes be necessary to upgrade the file system metadata as well. Note that in this case the file system can no longer be accessed with older versions of S3QL after the upgrade.

During the upgrade you have to make sure that the command is not interrupted, and that no one else tries to mount, check or upgrade the file system at the same time.

To upgrade a file system from the previous to the current revision, execute

s3qladm upgrade <storage url>

Deleting a file system

A file system can be deleted with:

s3qladm clear <storage url>

This physically deletes all the data and file system structures.

Restoring Metadata Backups

If the most-recent copy of the file system metadata has been damaged irreparably, it is possible to restore one of the automatically created backup copies.

The command

s3qladm download-metadata <storage url>

will give you a list of the available metadata backups and allow you to download them. This will create two new files in the current directory, ending in .db and .params. To actually use the downloaded backup, you need to move these files into the ~/.s3ql/ directory and run fsck.s3ql.

Warning

You should probably not use this functionality without having asked for help on the mailing list first (see Further Resources / Getting Help).