Subject: Re: CCL:Linux Cluster

From: Anton Feenstra <feenstra(at)chem.vu.nl>
Date: Mon, 03 Nov 2003 08:32:11 +0100

Kenneth Geisshirt wrote:

> Gregory Shamov wrote:
> 
>> KG> A number of companies build clusters (e.g., the one I work for),
>> KG> and you can buy cluster distributions like MandrakeSoft's
>> KG> Clustering product. Finally, you can build a cluster by hand (ok
>> KG> if the number of nodes is less than 6).
>>
>> And what happens if the number of nodes becomes 7 ? Or even 8 ?
> 
> 
> My point is that building a cluster by hand does not scale well. If you 
> plan a large cluster (32+ nodes) you will need some kind of automated 
> tool. If you build a 4-node cluster and add a new node (different 
> hardware e.g., an old office pc) you can do it by hand.

Im my experience, if you keep the hardware relatively homogeneous
(i.e. at least 16 nodes at a time are identical, and no more than say
2-3 different types of nodes) any number of nodes is as much work as
only one. It isn't too difficult to set up a system with net-boot
and harddisk images that installs new nodes automatically, and re-
installs nodes in case of crashes or other problems. I've done this
now for two different 'off-the-shelf' clusters and after initial
tweaking of setups (mostly related to network-card and boot-rom
specifics) everything is rock-stable and nearly self maintaining...

I've never done anything similar with e.g. 'old' office PC's (i.e.
in-homogeneous hardware), but it probably is more work than it is
worth relative to the average low speed of the 'old' CPU's.

-- 
Groetjes,

Anton
  _____________ _______________________________________________________
|             |                                                       |
|  _   _  ___,| K. Anton Feenstra                                     |
| / \ / \'| | | Dept. of Pharmacochem. - Vrije Universiteit Amsterdam |
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| \_/ \_/ | | | Tel: +31 20 44 47608 - Fax: +31 20 44 47610           |
|             | Feenstra(at)chem.vu.nl - www.chem.vu.nl/~feenstra/       |
|             | "If You See Me Getting High, Knock Me Down"           |
|             | (Red Hot Chili Peppers)                               |
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