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ESXi 5 (vsphere5) with PRTG



Hi! I have an interesting Problem:

I am monitoring some ESXi 4 and some ESXi 5 hosts. The ESXi 4 hosts are free, and the ESXi 5 are in a vSphere Essentials environment. I'm monitoring with the following sensors: esxserverhostsensor, sshdiskfreesensor, diskspacesensor, esxservervmsensor. On the ESXi 4 hosts everything is fine. On the ESXi 5 hosts my root partition is running full (ramdisk). I thought i have a problem with the log files, and moved the scratch to a bigger (persistent) storage. The only file with stayed in the ramdisk under /var/log is wtmp. And this file is growing very fast, as long as i have the sensors running. If i stop the monitoring the file grows very slow. My sensors are set to 30 seconds monitoring interval. I know that this is very short, and i thought to set the disk space sensors to 6h or 12h. But this doesn’t solve the problem, just makes the growth rate slower, and would not help me if i would have a problem with local storage running full on any ESXi host. I just would get the warning some h to late.

Do you have an idea how to fix this without changing the interval to more than a few minutes?

Regards, Thomas

diskspace esxi-5 ramdisk wtmp

Created on Mar 3, 2012 2:00:01 PM

1 Reply



we are aware of this issue.But I'm also afraid we cannot do anything to get this fixed, as it is VM Ware related. We only have workarounds to prevent the overflow of the RAM disk.

First option is emptying the file regularly with the following command (from the SSH Shell on the ESX(i) host)

> /var/log/wtmp

Second option would be removing the file because it won't get recreated untile the ESX host is rebooted.
Best regards

General Note: The file /var/log/wtmp is used to log the incoming SSH connections and the monitoring via SSH is therefore the cause of the file growing.

Created on Mar 5, 2012 7:46:46 AM by  Konstantin Wolff [Paessler Support]

Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.