Did you notice? I didn’t notice either until yesterday, ESXi 4.1 Update 2 is out, and its basically an update that supports more CPUs and OS’, CPU’s and OS’ that have been release after ESXi 4.1 Update 1. Here is an insert from VMware.com
The following information describes some of the enhancements available in this release of VMware ESXi:
- Support for new processors – ESXi 4.1 Update 2 supports AMD Opteron 6200 series (Interlagos) and AMD Opteron 4200 series (Valencia).
Note: For the AMD Opteron 6200 and 4200 series (Family 15h) processors, ESX/ESXi 4.1 Update 2 treats each core within a compute unit as an independent core, except while applying licenses. For the purpose of licensing, ESX/ESXi treats each compute unit as a core. For example, although a processor with 8 compute units can provide the processor equivalent of 16 cores on ESX/ESXi 4.1 Update 2, it only uses 8 licenses. <!–
- Support for additional guest operating systems — ESXi 4.1 Update 2 adds support for the following guest operating systems:
- Windows 7 Service Pack 1 Enterprise, Home Premium, Professional, Ultimate
- Windows Server 2008 R2 Service Pack 1 Datacenter, Enterprise, Standard, Web Server
- Redhat Enterprise Linux 4.9, 5.7 and 6.1
- SUSE Linux Enterprise Server and Desktop 10 Service Pack 4
- CentOS 4.9, 5.6 and 6.0
- Oracle Linux 4.9, 5.7, 6.0 and 6.1
- Ubuntu 11.04 Server, Desktop
- Asianux Server 3 SP4
For a complete list of guest operating systems supported with this release, see the VMware Compatibility Guide.
- Support for additional guest operating system -ESX 4.1 Update 2 adds support for Ubuntu 11.10 guest operating system. For a complete list of guest operating systems supported with this release, see the VMware Compatibility Guide.
Resolved Issues - In addition, this release delivers a number of bug fixes that are documented in the Resolved Issues section.
I do not see any reason for going to ESXi 4.1 Update 2, unless you work for a company that follows strict policy, or hasn’t renewed support with VMware. Other wise I would start migrating towards ESXi 5.0.