There seems to be a lot of confusion about vMotion and bus-shared VMDKs.  For the record, and from VMware, it is not recommended nor supported to vMotion your VM between ESX Hosts when using either Virtual or Physical mode bus-sharing.
Please see the KB here.
I know there are plenty that will disagree and have found ways [...]

VMware has released a KB with a handy vmfstools command to check your VM’s disk status.  If the VMFS output shows a “Z” it is Zerothick with blocks that have not been written to yet.
Read the article here.
This allows you to check the disk status for options such as Fault Tolerance or Microsoft Cluster Services.  [...]

VMware just posted an alert on this for ESXi 4 Hosts managed by either vCenter 4 or 4 Update 1.  If you remove and re-add the Host to vCenter, or upgrade vCenter to Update 1 you may experience this issue.
At this time, there is no official fix, however it appears a reboot should fix the [...]

VMware has posted a bug when upgrading ESX 4 to Update 01 with HP Management Agents running.  (ESXi is unaffected)
You may have your host end the update unsuccessfully, and in a non-responsive state.  To avoid this, disable all the HP Management Agents prior to running the update.
Read the full article here.

VMware has acknowledged an issue that we have been battling for some time with a Pegasus CIMSERVER memory leak.  It has been fixed under ESX 4, as it does not use Pegasus, otherwise setup a CRON job for restart Pegasus periodically.
This issue has been extremely frustrating in our environment for a very long time, and [...]

These are great instructions if you have received errors when trying to add a LUN to an ESX Host, and suspect that the LUN may not be READY, or write enabled these instructions can help you troubleshoot and/or fix the LUN.
Read the KB here.
If you are unable to re-write the LUN label, the disk is [...]

VMware doesn’t use the “Purple Screen of Death” or “ESX PSOD” terminology in their documents so if you Google it, you won’t get directed to VMware.com and this document for this information.  I know in the past I have spent far too much time searching for PSOD information, so keep this link handy. This document [...]

You will find these instructions in other How To posts and links here, but I thought I would post a simple KB from VMware for quick reference.  service mgmt-vmware restart, will NOT cause a Guest to reboot or go down.
Click here for the article.