pam_snapper - Man Page

PAM module which creates filesystem snapshots via "snapper"

Synopsis

pam_snapper​.so [debug] [homeprefix=prefix] [ignoreservices=services] [ignoreusers=users] [rootasroot] [ignoreroot] [openonly] [closeonly] [cleanup=algorithm]

Description

Create a snapshot at every login of a user, thus they always have a save starting point​.

As many users do not logout for some time, it is a good idea to enable snapper's time based snapshots in addition​.

Options

debug

Switch on debugging in the module​.

homeprefix=prefix

Prefix for the name of the snapper configuration​. The username will be appended to this prefix​.

Default: "home_"

ignoreservices=comma separated list of services

Default: "crond"

ignoreusers=comma separated list of users

Default: (none)

rootasroot

Perform a snapshot using the snapper configuration "root" if the user "root" logs in​. In other words: the homeprefix is not used in this case​. As the snapper configuration "root" is used for the system (the root filesystem), this means that with every login of the user "root" the complete "/" filesystem will be snapshotted​. This can be useful to help administrators rolling back in case their activity / configuration changes have been accidentally wrong​.

"rootasroot" and "ignoreroot" are mutually exclusive​.

ignoreroot

No snapshot is taken, if the user "root" opens/closes a session​.

"rootasroot" and "ignoreroot" are mutually exclusive​.

openonly

Only create a single snapshot when opening the PAM session​.

Default: create pre- and post-snapshots

closeonly

Only create a single snapshot when closing the PAM session​.

Default: create pre- and post-snapshots

cleanup=cleanup-algorithm

Set snapper cleanup algorithm​.

Default: (none)

Module Types Provided

Only the module type "session" is provided​.

Return Values

PAM_SUCCESS

pam_snapper will always return PAM_SUCCESS, to not prevent users from login, in case a snapshot fails​. This may change in the future​.

Examples

Basic usage

  1. Create a btrfs subvolume for the new user and a snapper configuration, e​.g​. using the tool /usr/lib/pam_snapper/pam_snapper_useradd​.sh​.
  2. Add the following line to /etc/pam​.d/common-session:

    session    optional    pam_snapper​.so

See Also

snapper(8), pam.conf(5), pam(8), pam_snapper_homeconvert, pam_snapper_pamconfig, pam_snapper_useradd, pam_snapper_userdel

Homepage

http://snapper​.io/

Authors

pam-snapper was written by Matthias G​. Eckermann <mge@suse​.com> as part of SUSE Hackweek#9 in April 2013​.

This module would not have been possible without the work of Arvin Schnell on the snapper project​. pam-snapper inherits DBUS handling from "snapper_dbus_cli​.c" by David Disseldorp​.

The module builds on the Linux PAM stack and its documentation, written by Thorsten Kukuk​.

License

Copyright (c) 2013 SUSE

All Rights Reserved​.

This program is free software; you can redistribute it and/or modify it under the terms of version 2 of the GNU General Public License as published by the Free Software Foundation​.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE​. See the GNU General Public License for more details​.

You should have received a copy of the GNU General Public License along with this program; if not, contact SUSE​.

To contact SUSE about this file by physical or electronic mail, you may find current contact information at www​.suse​.com​.

Info

2013-05-23 0.13.0 Filesystem Snapshot Management