Re: [tlug] New Custom Server for Linux - Advice Needed

[Attila Kinali <attila@example.com>]

On Fri, 18 Aug 2006 08:06:27 +0900
"Matt Gross" <mattgross@example.com> wrote:

 
> Here is what I am thinking I would like (my goal is to spend about 500,000
> yen):

Hmm.. you can buy quite something with that money.
 
> *	Dual CPU with hyper threading

Leave HT out of the equation. It gives better performance
only in very limited workload scenarios. As you want to build a 
server you might want to make sure that you have enough
I/O performance instead of CPU power.
Dual CPU boards tend to have better I/O performance, but
on todays systems it's mostly limited by the wire delay
and this is mostly determined by wire length.

What you might want to look for though is that you
have as much L2/L3 cache as possible. For a server
1MB/CPU is absolute minimum, IMHO.

32bit or 64bit is mostly a question on what you want to
run and how much work you want to invest into it.
If you go for an amd64, then you have to live with a few
limitations of software that doesnt work correctly on that
system yet. It's better for sparc bassed systems where most
programs do work. But on amd64 you can always build a 32bit
chroot and run the other programms too.

> *	RAID 5 (Software or Hardware - what do you recommend?)

Depends on what you want. If you go for hardware, make sure
you use a controller with enough onboard cache that is
battery backed (or you will lose data in a case of crash)

BTW: it is worth paying a bit more for better disks with
longer warranty and that are specified for 24/7 use.

BTW2: dont use PATA, it's a lot slower than SATA, SCSI or FC-AL

> *	4GB of Memory

4G memory does only help if you have a lot of disk access
that you want to cache or have ( multiple if it's a 32bit cpu)
processes that use a lot of memory.

> The goal is to install a Fedora system with Xen.  Then to create multiple
> guest systems to replace several individual servers I have scattered around
> my apartment.

Uhmm.. are you sure you want to use Xen? Do the different servers
really have to be seperated? If not, use a single linux instance.
If they have to be seperated i'd rather use something like
OpenVZ[1] or Linux Virtual Server[2]. Both are very similar
systems that are something like an enhanced version of chroot.
They give a lot better performance than Xen and are easier to set
up. OpenVZ is backed by a company and uses an older kernel version
where security fixes are backported to, claiming that it's the
way to go if you want a secure system. Linux VS uses a vanilla
kernel and applies a patch and thus can keep up with all changes
to the kernel[3].


> What I would like advice/recommendations on is the technical specs for the
> Motherboard, CPU, RAID setup, etc.  

There for you need to provide more information on what you want
to do with the machine. Just saying "Running Xen to replace
other servers" is not enough. What services do you want to run
on it, how much memory/cpu do they need, how much diskspace,
how important is your data on disk, how important is uptime,
can you handle scheduled downtime etc pp.

			Attila Kinali

[1] www.openvz.org
[2] www.linuxvirtualserver.org
[3] I personally like the approach of Linux VS better as I know
that not all patches that are security relevant are announced as such
and w/o hundreds of people who go trough every patch it's impossible
to make sure that nothing that might impose a security risk is left out.
But you might find the backing up of a company more appealing, then
you have at least someone to blame ;)


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