[Dovecot] SSD drives are really fast running Dovecot
Rick Romero
rick at havokmon.com
Sat Jan 15 04:29:26 EET 2011
Quoting Stan Hoeppner <stan at hardwarefreak.com>:
>> David Jonas put forth on 1/14/2011 2:08 PM:
> >
> >> Raid10 is our normal go to, but giving up half the storage in this case
> >> seemed unnecessary. I was looking at SAS drives and it was getting
> >> pricy. I'll work SATA into my considerations.
> >
> > That's because you're using the wrong equation for determining your
> > disk storage
> > needs. I posted a new equation on one of the lists a week or two ago.
> > Performance and reliability are far more important now than
> total space. And
> > today performance means transactional write IOPS not streaming reads. In
> > today's world, specifically for transaction oriented applications (db
> > and mail)
> > smaller faster more expensive disks are less expensive in total ROI
> > that big fat
> > slow drives. The reason is that few if any organizations actually
> > need 28TB (14
> > 2TB Cavier Green drives--popular with idiots today) of mail storage
> > in a single
> > mail store. That's 50 years worth of mail storage for a 50,000 employee
> > company, assuming your employees aren't allowed porn/video
> attachments, which
> > which most aren't.
And that's assuming a platter squeezing in 1TB of data at 7200RPMs doesn't
get a comparable performance improvement to a higher rotational speed on a
lower volume platter... Hell for the price of a single 250gb SSD drive,
you can RAID 10 TEN 7200 RPM 500GB SATAs.
So while, yes, my 10 drive SATA RAID 10 ONLY performs 166MB/sec with a
'simplistic' dd test, In reality I just don't think Joe User is going to
notice the difference between that and the superior performance of a
single SSD drive when he POPs his 10 3k emails.
Rick
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