thin client server suggestion?

[Jan Wilson]

Matt Price wrote:
> Well, as I was saying earlier, I'm itching to set up a thin client lab
> in my computers course; I was being held back by lack of funds to buy
> a real server.  Now it looks like we may have found someone with some
> cash to buy us one...  so I was wondering what exactly I should ask
> for.  THe tuxlabs documentation suggests:
> - 2 gig ram

If you are using something like OpenOffice.org, I would recommend about 
256 MB for all the regular processes you have on the server, and add AT 
LEAST 60 MB per LTSP client.

> - SCSI drives

At least for the /home partition.  To save money, you might use SATA 
drives for the application servers, or for files that are archived online.

Programs like OOo are continually reading and writing little files 
to/from the user's home directory, so the issue becomes not only the 
faster speed and greater reliability of SCSI drives, but their caching 
is MUCH better for this kind of use.

I am working with schools in a developing country (Belize), so REAL 
servers are almost out of the question for most schools.  You CAN make 
LTSP servers out of "regular" computers, but you really do need SCSI at 
least on the home server.  Application servers can use IDE (or SATA if 
available).

> - gigabit ethernet (also gigabit ethernet on the switch, which I don't
> have -- we only have donated 3Com 3300 swtiches, which are nice but
> all 10/100 (far as I know, anyway).

The local junior college is installing a setup with gigabit all around 
but it's not fully operating yet, so I can't say how much it helps. 
Some have used the kind of switches that have a couple of gigibit ports 
to go to the servers and to communicate with other switches, and then 
have gigabit cards in the servers.

If possible, use CAT-6 cable so upgrading will be easier later.

> Already, this is geting tough -- e.g. we don't have the gigabit
> switch...  So I am wondering how to prioritize the various
> requirements.  So if folks don't mind, maybe y'all could suggest
> minimum and (within reason) optimal configurations for a server,
> including things like:
> 
> - what kind lf CPU (does it matter if it's 64-bit?  is a
> dual-processor machine - which about doubles the minimum price, I
> think -  vastly more desirable?)

If cost is a huge factor (it is for us) put the money in RAM or 
additional servers.

> - how much and what kind of RAM?

LOTS.  The speed of the RAM is not so important as the quantity. 
Remember that the difference between fast RAM and slow RAM is almost 
insignificant compared to the difference between slow RAM and swapping 
to hard drive.  When your server runs out of RAM and starts using the 
swap you'll wish you had a hand crank ... things get ridiculously slow.

> - How big a deal does SCSI make?  Does SATA, or SATA RAID, help make
> IDE performance closer to SCSI?

See above.  Sorry it's not more definitive.

> - is gigabit ethernet an absolute requirement?

Don't really know, since we haven't used it yet.

> - any other hardware config questions I've failed to notice...

Most of the questions boil down to what makes a good network server and 
networking hardware.  It's just that LTSP REALLY tests the network. 
You'll probably need a server motherboard, not because you absolutely 
need two or more CPUs, but because it's hard to find a regular 
motherboard that can handle more than 1.5 or 2 GB of RAM.

One tip ... companies like Dell like to quote a low base price and then 
stick it to you on upgrades.  1 GB RAM sticks are now not much more than 
the cost of 512 MB sticks.  If you buy your server with no RAM (or the 
minimum they'll sell you) and then add good quality RAM, you'll save a 
bundle.  Or mention that to the salesperson and they might cut the price 
down to something reasonable.

-- 
Jan Wilson, Consultant   _/*];   email:   kris at kringle.corosal.com
"Wizard Third Class"     |  |:'  corosal.com, corosal.bs, linux.bs
Corozal Town, Belize     |  /'  change each 's' to 'z' in  above !
Reg. Linux user #151611  |_/  Network, PHP, Perl, SQL, Linux, etc.