[gPXE] Setting delay time to boot

[Piotr Jaroszyński]

> Take a cluster booting after a power failure:
>
> waitfor DHCP_SERVER_IP  A_LATE_STARTING_SERVICE 0
> dhcp net0
> waitfor SAN_SERVER_IP A_LATE_STARTING_SERVICE 0
> chain <some cryptic SAN rune>
>
> My only concern would be it would need to have an ASCII spin thingi or
> some other indication that its not just locked up :-)
>
> Others might not agree that the logic is friendly or even that the idea
> is good ?

Perhaps a command like "keeptrying <command> [<interval>]" would be
more generic? It would just keep retrying <command> unless it succeeds
every <interval> seconds. OTOH with commands returning whether they
worked or not and conditionals it could be implemented as a simple
loop.
With it, your example could be implemented as:

keeptrying dhcp net0
keeptrying chain <some cryptic SAN rune> 15

I think it more closely reflects what you are after. You don't really
care whether A_LATE_STARTING_SERVICE is up, you just want to get your
ip from dhcp and then boot from iscsi or something. (And btw. you
can't do waitfor ip port w/o an IP address in the first place :)

-- 
Best Regards
Piotr Jaroszyński