SCSI drives recommendations

Richard Cottrill richard_c at tpg.com.au
Mon Jan 21 12:52:38 EST 2002


There are arcane arts associated with configuring databases for maximum
performance.  In terms of disc arrangement it comes down to you thinking
about how each file will be accessed and choose the disc arrangement that
most closely matches that particular requirement. I think the rough metrics
are linear or random access (will one disc be ok or should you stipe the
data across multiple discs)? Can the data be rebuilt on-the-fly (do you need
a parity/mirror disc)?. Do you really need HUGE amounts of bandwidth to/from
the disc (should you be striping data)? Is this something that really needs
much attention (the program files themselves can be put anywhere really)?

As for the web server: I'm not too sure. I think web servers really tend to
live in memory for most of their lives and tend not to hit the disc too
often (or they shouldn't at any rate). I don't expect that RAID will make a
big difference to the web server (I'm not too sure about this so everyone is
welcome to bite my head off on this point).

In terms of securing your client's data: I'd think that regular backups are
the way to go. RAIDs are not a replacement for off-line backups (although
the off-line backup could itself be on a RAID). I'm not too clear about the
best backup strategy for databases. I'm pretty sure there isn't a good way
to back up a live database though - for mine this implies some kind of
redundancy to make the DB available 24x7. Any recommendations on this topic
are welcome because this isn't something I've got to do - although I soon
might.

Richard

> -----Original Message-----
> From: linux-admin at lists.samba.org [mailto:linux-admin at lists.samba.org]On
> Behalf Of Daniel McNamara
> Sent: Sunday, January 20, 2002 8:35 PM
> To: Richard Cottrill; Canberra Linux User Group
> Subject: Re: SCSI drives recommendations
>
>
> The machine is an Acer Altos 1900B (
> http://www.acersupport.com/ess/html/9100b_specs.html ) and does have a few
> fans but I'm not quite sure it will be enough. The noise won't be such a
> problem for me as it will eventually be living in the server room
> at work. I
> intend to turn this machine into a web server / SQL database server. The
> main reason I want to fully populate the drive bays is because I've never
> worked with RAID and we are beginning to look into them at work. I'm not
> looking at getting anything spectacularly large (especially because of the
> lack of immediate cash problem) just enough smallish SCSI drives
> to allow me
> to start playing with RAID.
>
> But having that in mind would a web / SQL server benefit from a
> RAID array?
> Or is it better just having one large disk? The web server will
> be used for
> commercial use so my main hope for the RAID will be to protect
> the integrity
> of our customers data.
>
> Cheers
>
> Daniel
>
>
>
>
> ----- Original Message -----
> From: "Richard Cottrill" <richard_c at tpg.com.au>
> To: "Daniel McNamara" <daniel at cit-linux.net>; "Canberra Linux User Group"
> <linux at samba.org>
> Sent: Sunday, January 20, 2002 10:59 PM
> Subject: RE: SCSI drives recommendations
>
>
> > This sounds like a serious server case and so I'd expect that
> case cooling
> > has been taken care of by some reasonably huge fans scattered about (if
> > there aren't any then there's definitely going to be brackets for them -
> > just fill the brackets). You may have to worry a bit more about keeping
> the
> > room cool. I have a very lightly loaded system (roughly similar to your
> own
> > but with dual PPro instead) and it can warm my room quite effectively.
> More
> > pressing for me is that I've had disconnect to two (of five)
> fans and rig
> up
> > some very crap sound insulation to keep myself sane. I still
> can't sleep,
> or
> > even relax, when it's running.
> >
> > I wouldn't *plan* to fill the disc bays with anything; unless you have
> some
> > special requirement (like a raid and/or serious file serving) you'd be
> much
> > better served by buying one new, large disc. Something with a spindle
> speed
> > up around 15k RPM is probably a nice start :).
> >
> > Richard
> >
> > > -----Original Message-----
> > > From: linux-admin at lists.samba.org
> [mailto:linux-admin at lists.samba.org]On
> > > Behalf Of Daniel McNamara
> > > Sent: Sunday, January 20, 2002 11:29 AM
> > > To: Canberra Linux User Group
> > > Subject: SCSI drives recommendations
> > >
> > >
> > > Hey again guys,
> > >
> > > Many thanks to the (incredibly) quick replies to clarify about
> > > the multiple
> > > processor question. Now for something completely different.
> > >
> > > Having spent the last 4 hours swearing vehemently because I
> > > couldn't get the
> > > any Linux distro to run from the SCSI CDROM on this system
> because they
> > > would all hang on loading the Adaptec module, I finally realised
> > > something.
> > > The driver was fine. Perfect. Just the CDROM was fnargled. Proved
> > > this point
> > > by digging through my boxes of old computer bits to find an old
> > > caddy based
> > > SCSI CDROM. Plug it in and it worked first time. Sigh. Why didn't
> > > I think of
> > > that earlier?
> > >
> > > Anyway to cut a long story short I got the machine as is from the
> computer
> > > fair with one 4.3 gig SCSI hard drive and one (now confirmed useless)
> 24x
> > > CDROM. Now whilst the caddy loading drive does work it's not
> exactly my
> > > ideal choice so my question is this: What are you recommendations for
> SCSI
> > > drives (both hard drives and CDROM's). In relation I'm looking at
> fitting
> > > the machine with a CD burner but at this point in time I don't
> > > have a lot of
> > > cash so I don't mind buying second hand as long as it works.
> The machine
> > > also has 8 hot swap 68pin SCSI bays, one of which is being used by the
> 4.3
> > > gig drive. I'm looking to populate all the bays with anything
> I can get
> my
> > > hands on. Any size will suit me fine if anyone has some for sale or
> knows
> > > where I can get some for a good price.
> > >
> > > Oh just while getting recommendations, anyone have a really good case
> > > cooling system? With both CPU's at full blast and the drives
> bays fully
> > > populated I imagine it's going to get quite warm in the case. Not
> > > to mention
> > > the dual 420 watt power supplies.
> > >
> > > Cheers
> > >
> > > Daniel
> > >
> > >
> >
> >
>
>





More information about the linux mailing list