recommend me to Upgrade method

[MehdiJavadi]

i decide to upgrade my vsphere 5.1 U1 to 6.0U1,

and according to the Upgrade methods,

i need recommendation about this case that which method is safer to upgrade (no error guaranteed  and no bug)

because i'm working from remote location and not in server room.

please help me step by step.

THNX in Advance

[Techie01]

If you are upgrading only esxi, update manager is always the best choice. Please go through the documentation of 60U1 ( known issues section) to make sure that you are not exposed to any of those known issues

For vcenter upgrade there are lot of documents on known issues . 5.1 used older SSO design and 6.0 uses a different model (PSC/ management nodes) . So I strongly recommend to read the vmware documentations and KB's related to vcenter upgrade before starting the vCenter upgrade.