For a specific Magento website used webspace is increasing like anything in the quota

In used quota the website - it is showing 106GB.
when I check the same on command line using du -sh
I am getting 1.9G Only.
this is a sub-domain website. and I have not enabled any backup for this site.
so where used space is increasing in uncontrolled manner, I am not able to make out.
for example I am running the command here
/var/www/clients/client2/web196/ du -sh
and I am getting
1.9G
Thanks.
Note:
I had initially allocated 15GB space for this website. but website stopped working. When checking the quota it was 20Gb, so I increased the quota to 50GB. Now again it stopped working and used space is showing as 106Gb.

 

Email backups count as website quota. Check email also.

 

No.
No email domain is created for the site.
Interestingly when checking the whole VAR folder, which includes logs, www, vmail
with
du -sh
it reports - 77G
but in ISPCONFIG control panel this website web196 - used space is shown like this:
indianartzone.mywebsolutions.co.in (server2.mywebsolutions.co.in) web196 106.53 GB 48.83 GB 48.83 GB d

 

Hi Till
Thank you so much. You are absolutely right.
Looks like there was problem in rsync command which took multiple backups like
it shoudl be miedia/bkp-sdb5
but it was like
/media/bkp-sdb5/
/media/bkp-sdb5/media/bkp-sdb5/
/media/bkp-sdb5/media/bkp-sdb5//media/bkp-sdb5/
I need to check the same how this did happen.
Thanks.