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Tiffany Walker
Asked: 2013-02-15 14:06:02 +0800 CST

rsync/ssh/rsnapshot backup -- remote script execution

  • 772

I have the following settings in my configuration file: (/etc/rsnapshot.conf)

Script/Tool: http://www.rsnapshot.org/

backup_script   ssh     [email protected] "sh /home/user/backup_mysql.sh"     ./mysql

the example shows the following:

backup_script  ssh [email protected] "mysqldump -A > /var/db/dump/mysql.sql"    unused2

The error I get: 

ERROR: backup_script /usr/bin/ssh returned 255

What am I doing wrong?

linux

6 Answers

  1. rsnapshot configuration files are tab delimited. Make sure you include tabs between the backup_scrip, the ssh command, and the backup storage. If that does not work try running rsnapshot configtest to identify the problem.

    Answer updated

    It is more convenient to transform your backup line to the following format:

     backup_script    /dir/yourscript.sh    backupdirectory/

    Place the middle section in a shell script, make it executable and test it. In addition to this, the ssh [email protected] should connect to the remote host without a password non-interactively.

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  2. The rsnapshot.conf example actually uses backup_exec, not backup_script. However, backup_script can still be used to run arbitrary commands over ssh and sync any files generated in a temp directory. Any commands used must be referenced by absolute path. This worked for me, for one of my mysql databases:

    backup_script [tab] /usr/bin/ssh [email protected] "/usr/bin/mysqldump --single-transaction -u username dbname" > dbname.sql [tab] example.com/mysql/

    • 2
  3. Best Answer

    One possible way would be converting ssh [email protected] "sh /home/user/backup_mysql.sh" into a script (do_ssh.sh,here) and invoke that script.

    Something like,

    backup_script /path/to/do_ssh.sh ./mysql

    I'd also recommend you to try putting quotes around your entire command.

    backup_script "ssh [email protected] "sh /home/user/backup_mysql.sh"" ./mysql

    • 1

  4. The problem is something to do with ssh. From the ssh man page

    ssh exits with the exit status of the remote command or with 255 if an error occurred

    You should use ssh -v[vv] to get a verbose output from ssh and see what it has to say.

    • 1

  5. Have you set up key authentication with the remote host, or is the ssh command expecting you to type in a password interactively?

    If you haven't set up passwordless authentication, then the ssh command will fail to authenticate, and hence return an error (255 seems to be the default return value for any error).

    • 0

  6. I had a similar issue that was solved by making sure that there weren't tabs in the script "path".

    Instead of

    backup_script [tab] /bin/ssh [tab] [email protected] [tab] "/usr/bin/mysqldump -uroot --all-databases > ./mysqldump.sql" [tab] ./mysql/

    try

    backup_script [tab] /bin/ssh [email protected] "/usr/bin/mysqldump -uroot --all-databases > ./mysqldump.sql" [tab] ./mysql/
    • 0