[LON-CAPA-admin] RE: access server requirements

[Martin Siegert]

Hi,

On Thu, Oct 03, 2002 at 01:11:44PM -0400, Ron Fox wrote:
> 
> I may be completely wrong but it seems to me the specs you give are
> probably more like what you'd like a library server to be.  The
> access servers may not need quite the oomph.  
> RF

On Wed, Oct 02, 2002 at 15:49:42 -0700, Ray Batchelor wrote:
> > We are currently considering 2 access machines with:  dual 2.4GHz cpu;
> > 4GB mem; Raid 1 with 2 SCSI disks (mirroring...not sure whether this
> > is necessary but suspect that the increased cost might be relatively
> > small compared to potential benefit).                                              
My impression was that the main difference between the requirements for
access and library servers is the disk performance: whereas for
library servers you want something like RAID 5 you may get away with
cheaper low performance disk system on access servers.
Is this correct?

My impression also was that it is the load of the particular machine
(access or library server) that determines whether that machine is used
or not. Correct? Thus, by installing access servers with high cpu
performance you can actually decrease the load on the library server,
because the access servers can handle more requests.
Thus, high-performance cpus on access servers would make sense, right?

What kind of disk performance do access servers require? Do I need to
by SCSI disk or are IDE disks sufficent? How large do those disks
have to be?

I am also wondering whether we should invest in high-availability
servers from one of the "big" companies (IBM, Dell, etc.) or whether
we can get away with a "noname" product for almost half the price.
Is it correct for LON-CAPA that if one of the access server crashes
the other one and the library server will take over the load seamlessly
without noticeble effect for the users? In that case we obviously
would be better off with a noname product because we could buy twice
as many access servers.

Thanks for the info.

Cheers,
Martin

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Martin Siegert
Academic Computing Services                        phone: (604) 291-4691
Simon Fraser University                            fax:   (604) 291-4242
Burnaby, British Columbia                          email: siegert at sfu.ca
Canada  V5A 1S6
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