Greetings.

I currently am running a server which has recently been augmented with a tape backup system (model info below). I have written a very simple bash script to run backups (scripts contents below), and running this from the command line yields a successful backup. I have tested this manually many times, and all disaster-recovery tests have been 100% successful.

So I have added this to my crontab (shown below), which has two other jobs scheduled that run perfectly. For the life of me, I CANNOT get my backup script to run automatically via cron (which I have previously mentioned runs PERFECTLY from the command line).

I have checked /var/log/cron and it indeed says the job has run. However, the job clearly does NOT run, because 'dump' never appears as a running process in 'top' or 'ps'.

Permissions are fine (the other two jobs have identical permissions, execute-bits and ownership). Root owns the files, and it is root's crontab which executes these jobs. Running the command with 'at' works fine as well, I just prefer cron.

Here is my current system:

Tape Backup Unit:

Sony SDX-260V IDE
Using 21/50 GB tapes

'/root/root.crontab' contents:

00 21 * * * /SCRIPTS/dump_current_mail.sh <--- runs GREAT
05 22 * * * /SCRIPTS/mail_transfer.sh <--- also runs GREAT
00 23 * * * /SCRIPTS/backup.sh <--- WILL NOT RUN WITH CRON

Crontab is activated using 'crontab root.crontab' at the bash prompt as root. This is the way I have always done it, and ALL the other machines I run use this method and I do not have this problem with any of them.

'/SCRIPTS/backup.sh' contents:

mt -f /dev/tape eod <--- Go to end of data on this tape
dump -f /dev/tape /MASTER/Data/ <--- dump this dir to this tape drive
dump -f /dev/tape /MASTER/MAIL <--- dump this dir to this tape drive

For those of you who know 'dump', this is incredibly simple (I am no expert with 'dump'). These commands work perfectly as individual commands, AND they work perfectly when this script is executed MANUALLY.

I am out of ideas. Any help would be appreciated, as I am having to do these backups manually every night =)

Thanks

subcon

One test you could try is to run the script manually but in the background.
If it doesn't run, you may need to redirect the output to /dev/null, or take stdin from /dev/zero.
You could try redirecting the output to /dev/null in the script.

Running the script with & at the end ran, however doing so in crontab yielded no result. I even made a separate script, called execute_backup.sh with the following contents:

/SCRIPTS/backup.sh 2&1> /dev/null

Try adding 2&>/dev/null to the cron command itself
00 23 * * * /SCRIPTS/backup.sh 2&>/dev/null

=( Still no luck. 'top' shows no evidence of dump being run. This is so weird ...

iirc, the PATH used by cron is very minimalist ie it's poss that the tape cmds are not in the avail path. Try
echo $PATH
at the top of the shell script.
A way to debug it (shell file) is to say
set -xv
as the 2nd line (ie 1st after shebang line) of the shell script.

I'll try that in the morning, I'm about to pass out. Thanks guys ....

Nice catch, subcon!

Instead of redirecting the output, perhaps you should redirect it to a file. Both the stdout and stderr streams. At least until you have it working.
This may provide information on what is going wrong.

I took a look at my /etc/crontab file.
If "dump" isn't in the path, you can add the path in a PATH= command.

IT WORKED.

The end result (backup.sh):

SHELL=/bin/bash
PATH=/usr/bin:/usr/sbin:/sbin:/bin:/usr/lib/news/bin
MAILTO=root
#
mt -f /dev/tape eod
echo BEFORE DUMP: `date +%A-%Y.%m.%d` `mt tell` >> /root/backup_status.log
dump -f /dev/tape /MASTER/Data/
dump -f /dev/tape /MASTER/MAIL/
echo AFTER DUMP: `date +%A-%Y.%m.%d` `mt tell` >> /root/backup_status.log

THANK YOU THANK YOU

subcon