After reading about the VMware Migration Checklist on the vmetc.com website >> http://vmetc.com/2009/04/27/vsphere-migration-checklist/ I have taken a look myself, a selection of my thoughts and important points to note are below.
VMware have posted a draft vSphere upgrade Pre-requisites Checklist on there website, it is designed for anyone that is going to be responsible for planning or upgrading to vSphere 4. At the moment it is just a draft but will be updated with the full release of vSphere. It breaks down hardware and software checks as well as requirements for individual functionality within the new release. This is a must have for anyone looking to undertake the upgrades.
Direct Download >> http://vmware.com/files/pdf/vsphere-migration-prerequisites-checklist.pdf
Important points to note
- (Oracle 9i and Microsoft SQL Server 2000 are no longer supported. The database can be upgraded to the supported versions first)
- Ensure that there is either a local VMFS volume with at least 8 GB (10GB recommended) free space, or a shared VMFS volume with at least 8 GB free space (10 GB recommended) per ESX COS to store the ESX 4 COS vmdk
- Ensure that it is ok to upgrade the virtual machine hardware from v4 to v7. Once upgraded, you cannot revert back to an earlier virtual machine format unless you have created a snapshot of the virtual machine prior to the changes
- Ensure that virtual machines with thin provisioned disks do not need to be protected with VMware FT (since VMware FT requires virtual machines to have thick-eager zeroed disks)
The whole section on Fault Tolerance is worth reading, if you are looking to start using it as there are a number of caviats. Some of these are mentioned below : –
- Only 1vCPU, No storage vMotion, No thin provisioned disks, no DRS support for these VMs, no snapshot, no host add, no usb
- Network: Ensure that at least two NICs are used (NIC teaming) for ESX management/VMotion and VMware FT logging. VMware recommends four VMkernel NICs: two dedicated for VMware VMotion and two dedicated for VMware FT.
- Host certificate checking must be enabled
It obvious FT isn’t going to just be a feature you enable without a lot of thought into best practises and implications.