What should I do when rdiff-backup fails?

If rdiff-backup fails, the meta data file may get corrupt. When this happens, rdiff-backup will complain loudly every time it is run and possibly fail to backup some or all the files.

To force rdiff-backup to rebuild the meta data, set this option in the .rdiff backup action file:

options = --force

After a rdiff-backup run has been successful you should remove this option.

How could mylvmbackup method be used until special backupninja backup action is implemented

This FAQ describes how to backup MySQL with backup ninja and mylvmbackup:

English: backupninja + mylvmbackup
Russian: backupninja + mylvmbackup Russian

There is more general tutarial written August 21, 2006 By Peter Zaitsev:

Using LVM for MySQL Backup and Replication Setup:

How to restrict privileges on the backup server

Backupninja uses a "push" mechanism, where backups are sent from one or several hosts to a centralized backup server.

Mount your backup partition with limited execution rights

Mount your partition with limited nosuid,noexec,nodev rights:

Edit /etc/fstab
/home           ext3    defaults,nosuid,noexec,nodev      0       2

Create a user for each client

On the backup server, it is important to create a separate user for each client.

Use a restricted shell and jail users

Furthermore, you may use a restricted shell like rssh or scponly, which also offer the ability to jail connections.

On the backup server:
$ apt-get install scponly
$ adduser --disabled-password --home /home/backup/ninja-host1 --shell /usr/bin/scponly ninja-host1

You may now use ninja-host1 user to connect to the /home/backup/ninja-host1 jail.