RAID-5 and database servers

Support @ Technologist support at
Fri Mar 12 16:40:39 CST 2010

Hello John,
I don't know what the other profs will say,but I would take at least a
double channel raidcontroller and put at least half of the disks at one
channel and the other disks at the other channel.

and make a config like
channel a: disk a, b, c, (half of 1st array)
channel b: disk a',b',c' (second half of 1st array)

channel a: disk d,e,f (half of 2nd array)
channel b: disk d',e',f' (second half of 2nd array

Then I guess you have quite ok datatransferrates and I think it's
unlikely that scenarios like posted before that raid failes because of
freezing channels will break your arrays.

Probably I don't need to write this, but pls don't put your tapedrive at
the same controller or something like that.

So, I'm curious what the experts say about this config, but I think this
is quite foolproof..



Op vrijdag 12-03-2010 om 16:10 uur [tijdzone -0600], schreef John G.
> From: "Eric Rostetter" <rostetter at>
>  The other trap would be what happens if you get "spam bombed" and get say
> > a couple million spams sent to you in an hour or so... Do you expect to
> > survive this without slowdown, or is it okay that it slows down until the
> > spam bomb dies down?  You might only get a spam bomb like this once every
> > 5 years, but if it does happen, what are your expectations?  (Here spam
> > bomb could also be a joe-job, a virus outbreak, or other unexpected mail
> > event... Pick your favorite...)
> Well, this is actually the problem... I am about as sure as I can be that a 
> "spam bomb" is not a noce every five year event. We get flooded with spam 
> pretty regularly. Its probably not a million messages a day but more like 
> 50,000 in two hours and then little or nothing for the next 22 hours.
> Yeah, we can survive that. Its not like classes would be cancelled if some 
> prof can't get his mail or the response time on the web server is so slow as 
> to drive people away. But if it can be avoided, it would be very nice.
> I really think my boss is nearly out of patience with me. I think I know 
> what I want though. If I want to set up two RAIDs, one for the operating 
> system and one for the database files, do I need two PERCs? Can a single 
> PERC put 2 disks in a RAID-1 array and 3 others in a RAID-5 array?
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Arno van der Veen
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