Pre-ISSU Compatibility Checks for a Traditional Stack

After ISSU is triggered, but before ISSU processing begins, a pre-ISSU compatibility check is executed.

The compatibility check determines whether the stack is ready for an upgrade. A successful compatibility check for a stack displays the passing results, as shown in the following table.

Pre-ISSU Checks for a Traditional Stack

Check Passing Result
Stacking Topology is Ring Yes
Standby Present Yes
Standby ready for upgrade Yes
Flash use in progress No
Stack interactive-setup in progress No
Stack ZTP is configured No
ISSU in progress or aborted No
Election pending No
Election in progress No
Reload pending No
CPU utilization high No
All units in ready state Yes
Primary Image is upgrade compatible Yes
Secondary Image is upgrade compatible Yes
Startup config and running config Same Yes
Boot option present in running config No
User in Config mode No
POE-Firmware Download is in Progress No
System ready for issu If this flag is present, you can proceed with ISSU. Otherwise, check the conditions flagged by three asterisks (***) and make prescribed corrections to the device before performing an ISSU.