Re: [GENERAL] advice on buying sun hardware to run postgres

On Tue, 27 Apr 1999, Chris Bitmead wrote:

# Modern operating systems don't ask the disk to do something and then
# just wait for the answer. That's what interrupts are for. Anyway, modern
# disks have caches.

    You can only cache so much.  At some point, you're going to
actually want to write something to a disk, and while you're doing this,
nothing else can read.  This is why your system slows down sometimes even
when there's not a lot of intensive processing.  This doesn't happen with
SCSI until you saturate your SCSI bandwidth.

    Even disregarding theory, in practice, SCSI is always faster when
you're not doing single process per controller type access.  If you're
running a database and concerned about performance, you use SCSI disks.
If your processor(s) has something better to do than disk I/O, then you
use SCSI.

# Never lost a file to Linux in 5 years.

    I'm just glad I keep backups.  When I was using Linux, I didn't
keep enough, though.  I lost some really good stuff.  I'd have a hard time
believing you've never lost a file unless the statement is qualified by
describing your backup strategy.  It's very difficult to improperly shut
down a Linux machine while it's actually doing something and not lose a
file.  It's very difficult to run an OS for five years without having it
improperly shut down (given normal home conditions).

--
SA, beyond.com           My girlfriend asked me which one I like better.
pub  1024/3CAE01D5 1994/11/03 Dustin Sallings <dustin@spy.net>
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