Alerts for USB disks which aren't writable anymore

Obig · 09-19-2018, 07:00 AM

Hi all,
We're using some pretty basic bash scripts to backup some servers.
Backups are written to a USB disk.

Problem is when the USB disk isn't mounted or is hanging, we don't know until we check the backup.
As the script will just create the directory as the actual one isn't mounted anymore.

I'd like to implement alerts when a disk is not writable so we get a warning somethings up.

Also we do a check on the age of previous backups but if something goes wrong with the backup and it isn't checked in time, it will delete de parent directory too and future backups will fail as it can't find the path.

Command used to delete:

dest="/mnt/backup"

# Create archive filename.
day=$(date +%d-%m-%y)
hostname=$(hostname -s)
archive_file="$hostname-$day"

#check for files older as 7 days
echo "BACKUP LOG" >> $log
echo >> $log
echo "Start rotating files" >> $log
echo "delete files older as 7 days" >> $log
find $dest/ -mtime +7 -exec rm -rf {} \; >> $log
echo "Finished rotating files"

and is there a better way to log this?

Thanks for the input!

hydrurga · 09-19-2018, 09:05 AM

You could issue a mount command before you start and grep the output to check for the mount in question.

Just a note that it's better if you paste code and output here within CODE tags (see https://www.linuxquestions.org/quest...og.php?b=36313).

teckk · 09-19-2018, 09:13 AM

Check your script

Code:

day=$(date +%d-%m-%y)
echo "$day"
19-09-18

Code:

hostname=$(hostname -s)
echo "$hostname"
localhost

Code:

archive_file="$hostname-$day"
echo "$archive_file"
localhost-19-09-18

Code:

echo "BACKUP LOG" >> $log
bash: $log: ambiguous redirect

echo >> $log
bash: $log: ambiguous redirect

You are trying to echo to a variable that you haven't defined.

If you want a log file then make it, then you can echo to it.

Code:

touch log

echo "BACKUP LOG" >> log

cat log
BACKUP LOG

Or if you want the log stored as a variable

Code:

var1=$(echo "BACKUP LOG")
echo "$var1"
BACKUP LOG

If you want to concatenate the entry to the variable

Code:

var1+="$(echo -e "\nBACKUP LOG")"
echo "$var1"
BACKUP LOG BACKUP LOG

Obig · 09-24-2018, 07:14 AM

Quote:

Originally Posted by teckk

Check your script

Code:

day=$(date +%d-%m-%y)
echo "$day"
19-09-18

Code:

hostname=$(hostname -s)
echo "$hostname"
localhost

Code:

archive_file="$hostname-$day"
echo "$archive_file"
localhost-19-09-18

Code:

echo "BACKUP LOG" >> $log
bash: $log: ambiguous redirect

echo >> $log
bash: $log: ambiguous redirect

You are trying to echo to a variable that you haven't defined.

If you want a log file then make it, then you can echo to it.

Code:

touch log

echo "BACKUP LOG" >> log

cat log
BACKUP LOG

Or if you want the log stored as a variable

Code:

var1=$(echo "BACKUP LOG")
echo "$var1"
BACKUP LOG

If you want to concatenate the entry to the variable

Code:

var1+="$(echo -e "\nBACKUP LOG")"
echo "$var1"
BACKUP LOG BACKUP LOG

Thanks, but the log variable is defined earlier in the script. Only copied the relevant parts of the script for the questions.
Should have mentioned that.

Obig · 09-24-2018, 07:15 AM

Quote:

Originally Posted by hydrurga

You could issue a mount command before you start and grep the output to check for the mount in question.

Just a note that it's better if you paste code and output here within CODE tags (see https://www.linuxquestions.org/quest...og.php?b=36313).

Thanks for the pointer, could be an option indeed.

kilgoretrout · 09-24-2018, 08:16 AM

See man mountpoint. The mountpoint command will tell you whether a given directory is a mountpoint or not. It's typically used in scripts for the problem you are trying to address, namely backups are going to the mountpoint directory when the drive is not mounted. Typical usage is as follows:

Code:

if mountpoint <insert full path to mountpoint>; then
   echo USB hard drive is mounted
   <insert backup script to run>
fi