How To Determine Mailbox Size (Postfix)

carlosinfl · 06-04-2008, 11:06 AM

I am using Postfix as an email server. Right now there is no mailbox quota limit size but I think 2048M is more than enough for the average user on my email server. Right now everyone has their email in their own home directory folder called Maildir (maildir style) and I was wondering how I can find each users mailbox size besides having to do "du -h /home/user/Maildir" command individually for all 300 users.

Does anyone have any suggestions as I have no experience with bash / shell scripts and would not know where to start.

I assume many of you guys manage / admin a large robust Postfix email server and would know some tips and or tricks to help me filter and get the data I am looking for.

trickykid · 06-04-2008, 11:42 AM

Something like this might work for you to get listing:

Code:

for USER in `ls /home`
   do
     du -sh /home/$USER/Maildir
done

Notice the -sh instead of just -h, this will not give a total size of each file within the Maildir, instead giving total usage for the whole Maildir, cleaner output to read.

carlosinfl · 06-04-2008, 11:48 AM

Are you saying I should run the command:

Code:

du -sh /home/$USER/Maildir

or was that a suggested shell script?

trickykid · 06-04-2008, 11:52 AM

Quote:

Originally Posted by Carlwill

Are you saying I should run the command:

Code:

du -sh /home/$USER/Maildir

or was that a suggested shell script?

You have to run the whole script, not just the du command portion of it.

Basically let's break it down:

Code:

for USER in `ls /home`

This assigns the variable to each user from the ls command to get the list of everyone's home directory that might have a Maildir within it.

Code:

do

This simply tells us what were going to do with the variables, basically the next step.

Code:

du -sh /home/$USER/Maildir

The command were running against each variable assigned from the list of users in the /home directory.

Code:

done

We're telling the script we're all done now.

Make sense?

carlosinfl · 06-04-2008, 12:14 PM

Thanks for the break down. That script worked perfect. If I wanted to filter the results for anything larger than 1.0G, how would that sit in the script?

trickykid · 06-04-2008, 12:33 PM

You could run the whole command like this most likely:

Code:

for USER in `ls /home`; do du -sh /home/$USER/Maildir; done | awk '$1 > 100000000000 {print $1, $2}'

I changed it to bytes instead of human readable as it's easier to use bytes with awk instead, but that should print off all the users with a Maildir above 1GB in size.

carlosinfl · 06-04-2008, 06:30 PM

Thanks again Trickykid!

From that I created a shell script which I ran as so:

Code:

[cwilliams@mail ~]$ sudo ./disk_space 1000000
*****************************************************************
1.9G dsanza
1.1G hkazzoun

As you can see I run the script with the size I am looking for and it displays the results human readable for me.

Here is the script:

Code:

if [ "$1" = "" ]; then
     echo "*****************************************************************"
     echo
     echo "Enter quota amount to be compared to the mailbox size - 600000 is 600M ...."
     echo
     echo "*****************************************************************"
     else
     echo "*****************************************************************"
          for USER in `ls /home`
            do
            if [ -d /home/$USER/Maildir ]; then
               DISKSPACE=`du -s /home/$USER/Maildir|awk '{print $1}'`
                  if [ $DISKSPACE -gt $1 ]; then
                  DISKSPACE=`du -sh /home/$USER/Maildir|awk '{print $1}'`
                  echo "$DISKSPACE $USER"
                  fi
            fi
          done
     echo "*****************************************************************"
fi

trickykid · 06-05-2008, 07:38 AM

Cool. Yeah, I prefer human readable most of the time but when I write scripts that check sizes, I always resort to bytes. But glad my examples helped you come up with a script to suit your own needs.