Quick question.
Colm MacCarthaigh
colm at stdlib.net
Sun Aug 1 17:05:51 UTC 2004
On Sun, Aug 01, 2004 at 09:44:13AM -0700, Michel Py wrote:
> In other words, I don't really care if the second processor reduces the
> MTBF from 200k hours to 60k hours, but I do care if the second processor
> reduces the time to restore service from 24 hours to 20 minutes (7.5
> minutes for SNMP to fail the query twice, 1.5 minute for the tech to
> find out that either it's frozen or there's a BSOD, 6 minutes to have
> someone go there and reset, 5 minutes to reboot).
With the right form factor (nice easy-to-open rackmount unit) it will take
just as little time to swap in an on-site cold-spare. That way you get the
nice MTBF and the short restore time. Also, if you have multiple similar
machines, you drastically reduce your spares inventory.
> Unsignificant in my experience, and does not balance what Alexei
> mentioned yesterday: a duallie will keep the system up when a faulty
> process hogs 100% CPU, because the second one is still available. That
> also increases availability ratio.
These days you can achieve the same using hyper-threading for example,
and keep the long MTBF :)
--
Colm MacCárthaigh Public Key: colm+pgp at stdlib.net
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