Comment 3 for bug 1144612

transcript from the upstream bug report :

After doing an analysis of the code, most particularly lib/puppet/type/mount.rb it appears that the problem doesn’t lie with puppet but with cifs-utils.

When puppet does a ‘mount -o remount’, it triggers a bug in cifs-utils that makes a double entry in /etc/mtab. This is the commit of the fix for this bug :

http://git.samba.org/?p=cifs-utils.git;a=commit;h=f46dd7661cfb87257c95081fc2071c934bfbbb16

“During a remount of a cifs filesystem, the mtab file is not properly updated, which leads to a doubled entry of the same filesystem in the /etc/mtab file. This patch adds a new function del_mtab() which is called before the add_mtab() in case the fs is being remounted.”

A potential workaround is to use remounts => ‘false’ but a safer solution would be to get a version of cifs-utils higher than 5.3 :

https://lists.samba.org/archive/samba/2012-January/165958.html

To confirm this outside of puppet control, simply do the following :

$ mount //sambahost/test /mnt/target
$ mount -o remount /mnt/target

$ df | grep target
//sambahost/test 7033648 1278120 5402660 20% /mnt/target
//sambahost/test 7033648 1278120 5402660 20% /mnt/target