I have two Chassi 6509 with SUP720-VSS
the original IOS was an SXI, so now I use s72033-ipbasek9-mz.12.2-33.SXI4a
If i am looking at cisco site to support for "Cisco Catalyst 6500 Virtual Switching System 1440" there is only listed "Catalyst 6500 Release 12.2SXH and Later Software Configuration Guide"- Where is the pdf for the SXI version?
Which IOS is recommended by Cisco for VSS?
If I compare the two Version SXH and SXI with cisco software advisor (it is only available for s72033-ipbasek9-mz.12.2-33.SXI3 and s72033-ipbasek9-mz.12.2-33.SXH6) I see that in the SXI version are more features included.
But I found out that there must be differences in some commands between the SXI and SXH.
As example (Catalyst 6500 Release 12.2SXH and Later Software Configuration Guide):
Router1(config)# switch virtual domain 100
Router1(config-vs-domain)# switch 1 priority 20
Router1(config-vs-domain)# switch 1 preempt 12
in the SXI4a Version there is no preempt command :-/
the configuration guide for SXI is that of SXH ( and later releases)
if you make a search about VSS in the forums you will see that most people agree on using SXI on VSS
Hope to help