Home News Notable KB Articles from the week from TheVMguy and me.

Notable KB Articles from the week from TheVMguy and me.

by Roger Lund

http://vmguy.com/wordpress/index.php posted his weekly Notable KB Articles from the week.

27 Articles new or updated this past week.  The first one is very relevant.


None of these hit home for me, ( just didn’t apply) so I went looking for more, and found the following.


How to Store Snapshot Files on an Alternate LUN

Datastores no longer available during upgrade


I’ll quote them below.


How to Store Snapshot Files on an Alternate LUN

KB Article

Jan. 26, 2009


VMware ESX

VMware VirtualCenter


Snapshot files are stored in the directory where the <VMname>.vmx file exists.

If you have limited space on the LUN where the <VMname>.vmx file exists, it may be necessary to specify an alternate location for the delta files that are created when you take snapshots of a VM.


This can be accomplised by defining an alternative working directory in the <VMname>.vmx   for the VM. The side effect of defining an alternative working directory is that the swap file will also be created in the alternative location.

The step to do this are:

1) Power off the VM

2) Edit the <VMname>.vmx file

      * add a line that looks like the following **

workingDir = "/vmfs/volumes/47384c5e-41fd4f1c-69c3-00163581bcf/directory_for_vmname_snapshotfile/"

3) Remove the VM from inventory in VirtualCenter

4) Add the VM to inventory in VirtuaCenter

5) Power on VM

6) Take snapshots as desired

Note: It may not be necessary to remove from inventory and add back into inventory, but in repro this produced consistent results.

You cannot use the advanced edit setting feature in VirtualCenter to add this line to the <VMname>.vmx file and have this take effect.

Note: This appears to only work as expected when you edit the .vmx file directly.


Datastores no longer available during upgrade

KB Article

Jan. 25, 2009


VMware Lab Manager

Product Versions

VMware Lab Manager 3.0.x


  • Cannot complete an upgrade from Lab Manager 2.x to 3.x.

  • Required VMFS datastores no longer available.

  • An error is received while upgrading Lab Manager from version 2.x to 3.x after specifying VirtualCenter credentials in the configuration wizard.

  • The wizard does not proceed forward until each unavailable datastore is deleted from the configuration.


This issue occurs when the credentials you gave for VirtualCenter do not have sufficient permissions to access the datastores and other required objects.

To verify the permissions, connect to VirtualCenter using the same credentials specified in the Lab Manager configuration wizard. If you are not able to see the configured hosts, clusters, or datastores, you must reconfigure the account privileges to make these objects accessible, or use a different account.

For more information on configuring VirtualCenter permissions, see the Basic System Administration guide, specifically the Managing Users, Groups, Permissions, and Roles section.

Those two caught my eye.


Thanks to The VMguy and VMware.

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