<div><span style="font-family: Arial; font-size: 10pt;">ESX hosts might become incompatible with ESXi hosts for VMware Fault Tolerance (FT) purposes after they are patched, even though they are patched to the same level</span><span style="font-family: Times New Roman; font-size: 12pt;"><span style="font-family: Arial; font-size: 10pt;">. </span></span></div>
<div><span style="font-family: Times New Roman; font-size: 12pt;"><span style="mso-fareast-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'; mso-fareast-language: EN-US; mso-ansi-language: EN-US; mso-bidi-language: AR-SA; mso-ascii-theme-font: minor-latin; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-theme-font: minor-bidi;"><span style="font-family: Arial; font-size: 10pt; mso-fareast-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'; mso-fareast-language: EN-US; mso-ansi-language: EN-US; mso-bidi-language: AR-SA; mso-ascii-theme-font: minor-latin; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-theme-font: minor-bidi;">This issue is a result of the ESX and ESXi patching process. It will be resolved in a future release so that compatible ESX and ESXi versions are able to interoperate with VMware FT Primary and Secondary virtual machines, even though patch numbers do not match exactly.</span></span></span></div>
<div><span style="font-family: Times New Roman; font-size: 12pt;"><span style="mso-fareast-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'; mso-fareast-language: EN-US; mso-ansi-language: EN-US; mso-bidi-language: AR-SA; mso-ascii-theme-font: minor-latin; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-theme-font: minor-bidi;"><span style="font-family: Arial; font-size: 10pt; mso-fareast-font-family: Calibri; mso-bidi-font-family: 'Times New Roman'; mso-fareast-language: EN-US; mso-ansi-language: EN-US; mso-bidi-language: AR-SA; mso-ascii-theme-font: minor-latin; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-theme-font: minor-bidi;">
<div class="MsoPlainText" style="margin: 0in 0in 0pt;"><span style="font-family: Arial; font-size: 10pt;">In particular, ESX 4.0 and ESXi 4.0 hosts with patches ESX400-200906401-BG (ESX) and ESXi400-200906401-BG (ESXi) become incompatible and can no longer run a Primary and Secondary virtual machine of the same FT pair. </span></div>
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<span style="font-family: Arial; font-size: 10pt;">When creating a cluster that will have fault tolerant virtual machines, the cluster should consist of all ESX hosts or all ESXi hosts and not a mix of ESX and ESXi hosts. </span>
<div><span style="font-family: Arial; font-size: 10pt;">If you have a mixed cluster, the ESX and ESXi hosts might become incompatible for VMware Fault Tolerance purposes, even if they are patched to the same level. There will be less flexibility in running fault tolerant virtual machine pairs in the cluster, and it may also mean that a compatible host for starting a new Secondary virtual machine cannot be found if a host in the cluster fails.</span></div>