BackupPc

Setup

• apt-get install apache2 backuppc libfile-rsyncp-perl
• add to /etc/aliases

backuppc: root

If you use a dedicated disk or partition:

• prefer reiserfs over ext3 to avoid any inode shortage problem.
• mount it with "noatime" for better performances
• If you've to move an existing setup, move /var/lib/backuppc to the dedicated partition but preserve hardlinks (use cp -a), then create /var/lib/backuppc symlink

To create/change http passwords:

 htpasswd /etc/backuppc/htpasswd backuppc

To create a new user:

htpasswd /etc/backuppc/htpasswd user

add to /etc/aliases

user: user@email.com

To prepare backuppc to access the hosts:

su - backuppc
ssh-keygen -t rsa -N ''

For a full restoration from scratch, see the backuppc paragraph in Harddrive

Whenever you change the config files, be sure to have the proper permissions:

chown backuppc:www-data /etc/backuppc/*
chmod go-rwx /etc/backuppc/*pl

Apache2

ln -s /etc/backuppc/apache.conf /etc/apache2/sites-enabled/backuppc

Add a host for backup

• add it to /etc/backuppc/hosts
• create a file such as /etc/backuppc/<host>.pl with the same name and with variables from config.pl that you want to adapt for your host
• scp /var/lib/backuppc/.ssh/id_rsa.pub root@<host_to_backup>:
• on the host:
  • cat id_rsa.pub >> ~/.ssh/authorized_keys
  • prepend the line in authorized_keys by sth like
    from="<my_backup_server>"
    so that only the backup host can log with this key.
  • install a ssh server if not yet done
  • install rsync
• Try once as user backuppc to log as root on your host, first to accept the fingerprint, second to check if you are in without prompt for pwd
• Reload hosts in backuppc: /etc/init.d/backuppc reload

Troubleshooting

Backup failed and you've only a very poor error message?

For example:

Got fatal error during xfer (Unable to read 4 bytes)

There are more complete logfiles in /var/lib/backuppc/pc/*yourmachine*/XferLOG.bad.z
But they're compressed with libz (I think) so to read the file:

$ /usr/share/backuppc/bin/BackupPC_zcat /var/lib/backuppc/pc/*yourmachine*/XferLOG.bad.z

To continue on the same example, here we got:

full backup started for directory /blabla
Running: /usr/bin/ssh -q -x -l root yourmachine /usr/bin/rsync --server --sender --numeric-ids --perms --owner --group -D --links --hard-links --times --block-size=2048 --recursive --bwlimit=1500 --ignore-times . /blabla
Xfer PIDs are now 10100
Read EOF: Connection reset by peer
Tried again: got 0 bytes
Done: 0 files, 0 bytes
Got fatal error during xfer (Unable to read 4 bytes)
Backup aborted (Unable to read 4 bytes)
Not saving this as a partial backup since it has fewer files than the prior one (got 0 and 0 files versus 0)

Ok ssh command failed. Let's try it:

# su - backuppc
$ /usr/bin/ssh -l root yourmachine ls

The authenticity of host 'yourmachine (1.2.3.4)' can't be established.
RSA key fingerprint is bl:ab:la
Are you sure you want to continue connecting (yes/no)? yes

So that's was the issue! That's what happen when you miss the last step in the paragraph about adding a host, just here above!

To invert tunnelling (if from behind a firewall)

• On the host:
  • ssh -R 2222:localhost:22 <backup_server>
    Make it passwordless with keys
  • To make it automated: install autossh
    Add somewhere in the startup scripts:
    su <my_local_user> -c 'autossh -N -f -M 29001 -R 2222:localhost:22 <backup_server>' &
  • Or in /etc/network/interfaces
    up su <my_local_user> -c 'autossh -N -f -M 29001 -R 2222:localhost:22 <backup_server>' &
    down su <my_local_user> -c 'killall autossh'
• On the server:
  • backuppc ~/.ssh/config:
    • Host <host_to_backup_as_said_to_backuppc>
    • ~HostName <localhost or ip_pub for vservers>
    • Port 2222

Deleting backups

I was used to do it manually but there is a nice script here, probably handling it less wildly than what I did...

Tips

When upgrading to rsync 2.6.7 on the clients you could face some problems.
This is due to a different interpretation of the option --devices
Use -D instead for sth compatible with all rsync versions.
Change it in config.pl and other host config files: $Conf{RsyncArgs} and $Conf{RsyncRestoreArgs}
cf http://sourceforge.net/mailarchive/forum.php?thread_id=10176480&forum_id=503

Notes on new install

LVM

• VG fitpc-vg
  • LV swap 2G => crypto; random key
    • swap
  • LV root 23G => ext4; label ROOT; use as /
  • LV home 500G => crypto
    • ext4; label HOME; use as /home; noatime,nodirtime; usage:news (more inodes)