Problem of the dangling output log file

LOG ROTATION

Many of you might have faced this issue.Lets say we have a script try.sh and we run it as follows

sh try.sh > output

or consider we have a web server which sends its logs to some log file .

Now everything is fine until the size of the log File is small.

But once it rises you may face disk full issues.

I faced this issue with my webserver.

Now if you try to manually truncate the file it will not work.

Since it has been opened for writing and is currently being written.

Deleting it and creating new file of the same name will not work since the node is attached to the script .

Then how can you rotate the log file and compress it.

Answer is use the linux utility logrotate.

For more details do

man logrotate

It needs a config file to get the log file to be rotated.

add a cron job as follows.

/usr/sbin/logrotate /etc/logrotate.conf

the block u must append in /etc/logrotate.conf

is

/home/script/output {

       daily

       rotate 12

       size 1G

       compress

       missingok

       notifempty

       copytruncate

}

here /home/script/output is the path of the output file to be rotated.

other fields mean the following

run it daily

keep log file of up to 12 days

rotate if size more than 1 GB

compress the log file after rotation.

do not worry if file is missing

notify if the file is empty

create a copy of it , and truncate the original file.

with this the original issue has been solved.

You can now save the disk space and rotate logs.