Half a Page of Scribbled Linux

Automatic updates had not been applied for a while on my desktop machine due to package incompatibilities. (Why isn’t this listed in the Logwatch email?) After manually installing most of them, BackupPC started failing with the subject error. Tried advice to install these Perl packages:

• perl-IO-String
• perl-IO-Zlib
• perl-Archive-Zip
• perl-Archive-Tar
• perl-Compress-Zlib

This didn’t work.

Tried yum install perl-Compress-Bzip2 and setting $Conf{CompressLevel} = 0; (no compression) in /etc/BackupPC/config.pl. It worked, but since I broke the rule of testing one variable at a time, I didn’t know which one fixed the error. So I put the compress level back to three and retarted backuppc. It failed.

I failed to get BackupPC 3.0 working last time I tried with the TAR install. Found it’s available as an RPM.

# yum install BackupPC
# service httpd start

Browsing http://localhost/BackupPC popped up a prompt for username and password for “BackupPC” at http://localhost. Neither BackupPC’s password nor root’s worked.
File /etc/httpd/conf.d/BackupPC.conf says:
AuthUserFile /etc/BackupPC/apache.users
So I created apache.users file with my user name (not backuppc) in it.
Now can see the BackupPC page, but it says it’s unable to connect to the BackupPC server.

# service backuppc start

Started full backup from web interface. It failed:
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)

The problem is that BackupPC is trying to SSH to root, but there’s no key to allow backuppc to log in without a password.
See http://backuppc.sourceforge.net/faq/ssh.html#how_do_i_setup_openssh or:

$ su -
# su -s /bin/bash backuppc
$ ssh-keygen -t dsa
At password prompts, press enter.
$ exit
Edit ~root/.ssh/authorized_keys and add ~backuppc/.ssh/id_dsa.pub
Optionally append from="localhost.localdomain" if you only want backuppc to ssh to root from the local host.
# chmod u=rw,go= ~root/.ssh/authorized_keys

To test, su to backuppc as above and run ssh root@localhost. You should be logged in without having to enter a password.