Setup guide

TECHNICAL WHITE PAPER / 44
VMware vSphere® 5.0 Upgrade
Best Practices
Upgrading VMware vSphere VMFS
After you perform an ESX/ESXi upgrade, you might need to upgrade your VMFS to take advantage of the new
features. vSphere 5.0 supports both VMFS version 3 and version 5, so it is not necessary to upgrade your VMFS
volumes unless one needs to leverage new 5.0 features. However, VMFS-5 oers a variety of new features such
as larger single-extent volume (approximately 60TB), larger VMDKs with unified 1MB block size (2TB), smaller
subblock(8KB)toreducetheamountofstranded/unusedspace,andanimprovementinperformanceand
scalability via the implementation of the vSphere Storage API for Array Integration (VAAI) primitive Atomic Test
&Set(ATS)acrossalldatastoreoperations.VMwarerecommendsthatcustomersmovetoVMFS-5tobenet
from these features. A complete set of VMFS-5 enhancements can be found in the What’s New in vSphere 5.0
Storage white paper.
Considerations – Upgrade to VMFS-5 or Create New VMFS-5
Although a VMFS-3 that is upgraded to VMFS-5 provides you with most of the same capabilities as a newly
created VMFS-5, there are some dierences. Both upgraded and newly created VMFS-5 support single-extent
volumes up to approximately 60TB and both support VMDK sizes of 2TB, no matter what the VMFS file block
size is. However, the additional dierences, although minor, should be considered when making a decision on
upgrading to VMFS-5 or creating new VMFS-5 volumes.
•VMFS-5 upgraded from VMFS-3 continues to use the previous file block size, which might be larger than the
unified 1MB file block size. This can lead to stranded/unused disk space when there are many small files on the
datastore.
•VMFS-5upgradedfromVMFS-3continuestouse64KBsubblocks,notnew8Ksubblocks.Thiscanalsoleadto
stranded/unused disk space.
•VMFS-5upgradedfromVMFS-3continuestohavealelimitof30720ratherthanthenewlelimitof
>100000 for a newly created VMFS-5. This has an impact on the scalability of the file system.
For these reasons, VMware recommends using newly created VMFS-5 volumes if you have the luxury of doing
so. You can then migrate the virtual machines from the original VMFS-3 to VMFS-5. If you do not have the
available space to create new VMFS-5 volumes, upgrading VMFS-3 to VMFS-5 will still provide you with most of
the benefits that come with a newly created VMFS-5.
Online Upgrade
If you do decide to upgrade VMFS-3 to VMFS-5, it is a simple, single-click operation. After you have upgraded
the host to ESXi 5.0, go to the Configuration tab > Storage view. Select the VMFS-3 datastore. Above the
Datastore Details window, an option to Upgrade to VMFS-5… will be displayed: