VMworld Europe 2009


I’m  ready for VMworld 2009. I packed my clothes, charge the telephone, laptop, photo camera and the MP3 player.

I go with two colleagues from our company, we fly on tomorrow (Monday) from Rotterdam (The Netherlands) 10.50. 

I have made a personal list with the session (and meetings/parties) who got my interest. There are lot interesting hands-on labs but the are not on the session list .



I try to blog from VMworld, if i have some spare time :-).

Powershell Windows Eventlog script

This week i found the report-events Powershell script (see figure 1). The script is made by Jeffrey Hicks. It generates a nice HTML file with errors and warnings from the Windows eventlog.


figure 1. Output reports-event script

You can specify multiple servers in a text file, select how many hours from the current time to look in the eventlog and e-mail the HTML file after generation. 

The following syntax can be used:

get-content c:\script\servers.txt | c:\scripts\report-event.ps1 – report c:\script\eventlog.html –hours 48 –smtp mail.beerenss.nl –sendto eventlogs@beerens.nl –from eventlog@beerens.nl


get-content c:\script\servers.txt, text file containing the server names

– report c:\script\eventlog.html, name of the HTML file

| c:\scripts\report-event.ps1, call the actually script

–hours 48, hours to report from the curren time

–smtp mail.beerens.nl. SMTP server to sent the HTML rapport 

–sendto ivo@beerens.nl, To address

–from eventlog@beerens.nl . from address


Schedule this script to run frequently to watch your eventlogs!


Download the script here.


Missing datastore (LUN), EnableResignature


Yesterday a customer called me that one of the VMware ESX hosts is missing 1 datastore (LUN). The other VMware ESX hosts in the cluster had no problems with the datastore. Looked in the NetApp filer to see the presentation of the LUN, everything was okay.

After investing the log files on the VMware ESX host i found the following message:

Jan 22 12:39:34 boz101 vmkernel: 152:21:01:58.702 cpu4:1040)ALERT: LVM: 4476: vml.020003000060a980004335434b464a4b77554e59744c554e202020:1 may be snapshot: disabling access. See resignaturing section in SAN config guide.

It seems that the VMFS volume has been detected with a different LUN ID. The LUN ID is stored in the LVM header of the volume. When the LUN ID changes you need to enable resignature option to see the datastore again.

In the evening we powered all VMs on that LUN down.  On the host that was missing the datastore, I enabled the resignaturing option by:

– Go to the configuration tab of the VMware ESX host and select Advanced settings

– Click on LVM, and changed  the EnableResignature  0 (off) in 1 (on).

Did a rescan on the VMware ESX host and the LUN appeared as “SNAP-17EABCCC-VMWARE-LUN-03”. Tried the change the “SNAP-17EABCCC-VMWARE-LUN-03” LUN back to the old name “VMWARE-LUN-03”,  the following message appeared:

The name “VMWARE-LUN-03” already exists.

The solution was to switch the view to DATASTORES in vCenter and unregister all VMs on the “SNAP-17EABCCC-VMWARE-LUN-03” LUN. After all VMs were unregistered, i was able to rename it back to  the old “VMWARE-LUN-03” name. Then i register all the VMs on the “VMWARE-LUN-03” LUN and start them.

I checked the datastores on the other VMware ESX hosts,  they were fine. As last step i changed the EnableResignature option back to 0 (off) on the VMware ESX host.