Setup guide

TECHNICAL WHITE PAPER / 30
VMware vSphere® 5.0 Upgrade
Best Practices
Disk Partitioning Requirements for ESXi
ESXi 5.0 uses the same boot disk layout as ESXi 4.x. Therefore, in most cases the boot disk partition table does
not require modification as part of the 5.0 upgrade. One notable exception is with an ESXi 3.5 host that is
upgradedtoESXi4.xandthenimmediatelyupgradedtoESXi5.0.InESXi3.5,thebootbanksare48MB.In
ESXi 4.x, the size of the boot banks changed to 250MB. When a host is upgraded from ESXi 3.5 to ESX 4.x, only
one of the two boot banks is resized. This results in a situation where a host will have one boot bank at 250MB
andtheotherat48MB,aconditionreferredtoashaving“lopsidedbootbanks.”AnESXihostwithlopsidedboot
banks must have a new partition table written to the disk during the upgrade. Update Manager cannot be used
to upgrade a host with lopsided boot banks. The ESXi Installer must be used instead.
Disk Partitioning Requirements for ESX
When upgrading an ESX 4.x host to ESXi 5.0, the ESX boot disk partition table is modified to support the dual-
image bank architecture used by ESXi. The VMFS-3 partition is the only partition that is retained. All other
partitions on the disk are destroyed.
For the VMFS partition to be preserved when the boot disk is repartitioned, it must be physically located beyond
the1GBmark—thatis,aftertheESXbootpartition,whichispartition4,andaftertheextendeddiskpartitionon
thedisk(8192+1835008sectors).AnysystemthathasaVMFSpartitionafterthe1843200sectormark(beyond
the1GBboundary)cankeepthatVMFSpartition,regardlessofwhetheritwasinitiallyinstalledwithESX3.5or4.x.
Limitations of an Upgraded ESXi 5.0 Host
There are some side eects associated with upgrading an ESX host to ESXi 5.0 as compared to performing a
fresh installation. These include the following:
• UpgradedhostsretainthelegacyMSDOS-basedpartitionlabelandarestilllimitedtoaphysicaldiskthatis
less than 2TB in size. Installing ESXi on a disk larger than 2TB requires a fresh install.
• Upgradedhostsdonothaveadedicatedscratchpartition.Instead,ascratchdirectoryiscreatedandmount-
ed o a VMFS volume. Aside from the scratch partition, all other disk partitions, such as the boot banks, locker
and vmkcore, are identical to that of a freshly installed ESXi 5.0 host.
• TheexistingVMFSpartitionisnotupgradedfromVMFS-3toVMFS-5.YoucanmanuallyupgradetheVMFS
partition after the upgrade. ESXi 5.0 is compatible with VMFS-3 partitions, so upgrading to VMFS-5 is
required only to enable new vSphere 5.0 features.
• ForhostsinwhichtheVMFSpartitionisonaseparatediskfromthebootdrive,theVMFSpartitionisleft
intact and the entire boot disk is overwritten. Any extra data on the disk is erased.
NEW 5.0 INSTALL 5.0 UPGRADED FROM 4.X
Partition Label GPT MSDOS
Boot Disk >2TB Supported Not supported
Scratch Partition Disk partition VMFS volume
Boot Disk VMFS VMFS-5 VMFS-3 (can be upgraded)
Table 2. Limitations of a Host Upgraded from ESX 4.x