Re: TCO and users/box

"sinister" <sinister@xxxxxxxxxxxxxx> wrote:
I work at a scientific institute; we do scientific computation, some
reasonably intense. We have an aging Sun v1280 server (chips are
900MHz), and people in a position to make decisions or to give advice
agree that we should move to Linux in the medium/long run.

So you have an environment today which consist of a network with at least
one server for some kind of calculations and a number of desktop boxes of
different kind with users which are used to logging in to a server on the
network.

My own bias is to use fewer boxes, with more than one user/box, and
perhaps more than one CPU/box.

In the long term that is a rather good solution. That makes the desktop
boxes last longer as the users are able to log in to a strong server on
the network when they need more CPU power. With the CPU power on the desk
you would have to update more machines more often.

My perhaps uninformed view is that 1 user/box is a bad idea because: (1)
Administrative overhead is higher. Perhaps doesn't scale on a 1:1 basis
with number of boxes, but does scale up with number of boxes.

My own experiences from administring about 40 Linux boxes out of which
about 10 are network servers and about 30 are desktop boxes is that with a
standard installation that has mechanisms for updating itself the work is
far from 1:1 per box. It would not be much more work with 50 or 100 boxes
and it would not be much less work with 20 boxes. However, I would say
that the work scales with the number of users. Different users have
different needs when it comes to applictions and what kind of hardware
they want to be able to connect to their computers. But yes, the works
scale some with the number of boxes. More boxes means that you have to
replace broken hardware more often.

Thoughts?

If I were you I would start by buing a Linux server for CPU intensive
tasks to put on the network. You might want to start with a rather low-end
server just for a first test. Something like a dual CPU Xeon or Opteron
with 4 GB or RAM. Such a machine might cost something like 2000-3000 euro.
Compared to the Sun you have today this is a low-budget system. As this is
a machine that many users might depend on you should consider ECC memory,
redundant hot-swap power supplies and raid for system disk. I suppose that
you already have an UPS.

Once that machine is up an running on the network and the users know about
it you should start observing if and how it is used and if there are any
bottlenecks. With knowledge about usage and bottlenecks you will know what
to buy next time. Maybe more RAM for the machine? Maybe a machine with
more CPUs? Maybe another Sun? If you need more than 4 GB of RAM you should
run a 64 bit Linux distribution.

Today you say that some users have old Sun machines on the desktop and
some users need old PCs for office tasks. Instead of having to run office
tasks on an old PC you might want to consider ways to also put that
functionality on the network. There are different ways to do that. One way
is to put a Windows server on the network where users log in with a
terminal client. Another way is to switch to office applications that
works on your network servers. Yet another way is to use qemu or vmware to
run an emulated PC on a network server. With qemu it is easy to have a
number of reference Windows installations avaiable for the users.

You also did ask for a way to limit the RAM usage. A good start might be
to run "ulimit -a" at the bash shell prompt.

regards Henrik
--
The address in the header is only to prevent spam. My real address is:
hc7(at)uthyres.com Examples of addresses which go to spammers:
root@xxxxxxxxxxxxx root@localhost

.

Relevant Pages

  • problem with RH ES 4.0 network sockets
    ... i am running application on SUN Java Application Server 8.1. ... hrs) freeze network connection to the port which they use to connect. ... even if the workstation is rebooted. ...
    (RedHat)
  • XP Network Browse Problems
    ... Do the boxes still ping OK? ... >Win2000 Server, and workstations combined with one Xp ... If the Win2000 machines boot first, ... >boxes in the network neighborhood, ...
    (microsoft.public.windowsxp.network_web)
  • XP Network Browse Problems- SOLVED
    ... I'd noted that this was a peer-to-peer network on the XP ... The Win2K boxes were all hybrid ... I went on the XP box and changed the default node type to ... >>Win2000 Server, and workstations combined with one Xp ...
    (microsoft.public.windowsxp.network_web)
  • Re: Win2003 Server domain connections increadibly slow...
    ... DNS server that is available to the clients (same goes for DHCP if you're ... If a copy is initiated between boxes on the network, ...
    (microsoft.public.windows.server.networking)
  • Adding processors to v480
    ... boxes. ... I have tried to move the cpu's from one server to the other but have ... A sun field engineer suggested it might be a bad centerplane but the ... openboot incantation or centerplane dip switch setting? ...
    (comp.sys.sun.hardware)