Since upgrading to ESXi 5.1 some time ago I’ve seen the logfiles for some of our virtual machines grow truly massive, like over a gigabyte in size massive.
Removing the logs isn’t too difficult simply either vMotion the VM or shut it down entirely and then power up again. Both methods result in a new log being created allowing the old log to then be deleted.
The difficulty is in finding which VMs have generated huge log files, especially when you have well over a hundred virtual machines.
The following is a simple one line piece of code to show the 10 biggest logfiles, it can be amended accordingly to show a greater number.
cd /vmfs/volumes/; ls -lhdS [A-Z]*/*/vmware.log | head -10
To prevent that datastores are shown twice, once by name and once by id, it is limited to only show datastores starting with a capital letter, all our datastores start with an upper case letter, you may have to adjust the command to fit your particular environment.[Via]