[Gllug] [Fwd: Server]

[Richard Jones]

On Sun, Nov 23, 2003 at 12:12:12PM +0000, Peter Childs wrote:
>   Its a G320HS from http://www.dnuk.com with 2Gb of memory and enough 
> disks to make a raid array. (Xeon 2.8 Single Processor, IDE, 3ware Raid 
> controller...)

Have you thought about getting a rackmount version instead. If you
ever need to colocate the server, or if you ever need to builds lots
of your servers into a rack, then you'll thank yourself for having
spent a few hundred extra quid of a properly rackmounted server.

>   Every one wants to sell SCSI which is about 1,000UKP more and I 
> don't see the point.

I've heard it said that SCSI systems are manufactured to higher
quality tolerances than IDE systems. This hasn't been my experience -
in my experience both are as bad as each other. At my last job we had
a separate pile of dead IDE disks and dead SCSI disks waiting to be
returned to the manufacturers under warranty.  If you really believe
that a SCSI and an IDE disk from the same manufacturer aren't just two
identical spindles with different electronics tacked on the back, I
have a bridge to sell you.

Bearing that in mind whether you go for IDE or SCSI make sure you have
*lots* of redundancy. In the past we used Linux software RAID 5 (much
faster than hardware RAID options such as the Vortex cards, and crappy
Dell PowerEdge rubbish). We grouped the disks in groups of 6, with 4
live + 2 spare in each group, and typically had 24 disks (4 groups)
connected to each server, with each server having two or four SCSI
channels depending on performance requirements. There's a lot of
redundancy in such a setup (about 50%?). Perhaps your uptime
requirements are less critical and you could get away with less.

Use ext3!! reiserfs is very flakey, and if you use a non-journalled
solution you'll spend forever booting and fscking if you have a power
failure.

>   Its for a Linux based 24x7 automated booking system we've been 
> designing and writing for the past year. with about 60 users (20 at any 
> given time) and planned online stuff eventually. For a fleet of about 
> 300 drivers (who do not have access yet (may get web access one day))

How are they planning to get access to the server?!

For 24x7 you really want to be looking to colocate the server with a
reliable ISP. So you'll be wanting a 1, 2 or 4U rackmount server.

>   System is written in C++ and Qt to run on a Postgres Database, using 
> Jabber, and LTSP thin clients.

Sound technology choices. Do you have a plan for Postgres backup (eg.
tape? extra disks? off site? incremental?)

>   Oh and I'm currently planning on using Debian....

Good choice.

>   Any comments would be most usful as I havn't got a clue. I'll try 
> and keep people up to date as the system goes in if only because its a 
> big Linux based system within London....

Rich.

-- 
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