The latest VSP 8600 IOC modules have an updated real time clock (RTC) component, which is not compatible with some older software releases. The new modules should only be installed in a switch or chassis running the minimum supported software, which is 6.2.0.0.
To determine if your hardware contains the updated RTC, use the show sys-info card command and check the H/W Revision field. If the IOC Module CardHWRevision is 14 or higher, then you have the updated RTC. With the updated RTC, you can only run 6.2.0.0 or higher software versions.
If you attempt to hot insert the latest IOC module (RTC updated) in a chassis running an older unsupported release, the IOC does not become operational. This card attempts to boot unsuccessfully and powers off after 5 boot attempts.
If your chassis has any module with the new RTC component, you cannot downgrade the software to a version less than 6.2.0.0. During software activate execution, the switch prevents the downgrade and displays the following message:
ERROR: Hardware (revision 14) in slot <slot_number> is not supported in this release. Cannot activate release <x.x.x.x>. Please refer to the release notes or contact support.
If your chassis requires a software downgrade, you must remove all modules with the new RTC component from the chassis first.
Note
Removing these cards also results in a loss of configuration for the removed slots following a chassis boot.