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Re: Automatic Backup Script Help



Thank you for the feedback Jon. :-)

On 23/05/2012 09:12 AM, Jon Dowland wrote:
   { sleep 60; /data/backups/scripts/backup-disk-1.sh }&

But I don't see why you even need the sleep.

I agree. I suspect using sleep will merely suspend udev operations as well.

should be backticks here so that date is evaluated e.g.

start_date_time=`date +%Y-%m-%d-%H:%M:%S`

Thank you. Not being an experiences bash scripter, I always seem to get lost on the proper delimeters.


if -a /data/backups/${backup_description}-in-progress; then
	echo "FAIL ${backup_description} backup already in progress."
	exit 1
else touch /data/backups/${backup_description}-in-progress
fi

There is a risk of race conditions here, if two instances of your script
are fired off at similar times. E.g., whilst instance #1 has performed
the check, instance #2 creates the file…  Better would be a proper locking
solution. (sorry I'm not offering one in this reply)

That is what I am trying to achieve by the progress file. I have noticed that sometimes with usb, the device is "discovered" multiple times. So I want to prevent multiple instances of the script. I will obviously need to find a better locking mechanism.


if ! mountpoint -q ${backup_target}/; then

risk of races here

	if ! mount ${backup_target}; then

and here


I am lost here. I thought that this would be a simple mountpoint check. Is there a better way to mount and check if the drive is mounted?

Kindest Regards

Craig A. Adams



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