The duration, in seconds, the high-availability upgrade
process will delay between the successful upgrade of one
upgrade group and the start of the next upgrade group's
upgrade.
When an upgrade group is upgraded, all modules which
are a member of the group are reset. If these resets
cause instability in higher-layer networking protocols,
then this delay may help those protocols stabilize
during the course of the high-availability upgrade.
Note that this delay will increase the overall length
of the high-availability upgrade process.