[c-nsp] OIR on 7600s: Pretty much evil?

[Nick Hilliard]

On 10/11/2010 22:01, John Neiberger wrote:
> I ran into a problem with an OIR last night on a 7609. I normally
> don't like to do them. I usually prefer to power the router down
> first, replace/add the card and then power it back up. It caused all
> sorts of fun when it failed the initial startup and had to be reset by
> the system. Even then it was acting weird afterward for a bit until
> the system stabilized. But I'm not asking for troubleshooting help.
> 
> I'm just curious to hear your thoughts on OIR on this platform. Is
> this something that you prefer to avoid? Do you have any OIR-related
> horror stories you'd like to share?

Usually it works fine, but you have to be really carefully to insert and
remove the cards at roughly the right speed.  There's a particular position
which causes a bus stall and another which causes the stall to end.  If you
leave the bus stalled for too long, this triggers a watchdog timeout and
the supervisor reboots.  Even when you do things at the right speed,
reboots can still happen.

So yeah.  Annoying, but there you go.  Usually you'll get away with it, but
if your application is unforgiving of a 5 minute reboot during production
hours, then you may want to consider a maintenance window.

Nick