[lug] server memory woes (3rd attempt!)

[Michael Belanger]

Nate Duehr wrote:

> 
> One comment here... common mistake on large RAM boxes...
> 
> 6GB of swap will pretty much be useless to you and is wasted space.  If 
> you calculate how long it would take to swap 6GB of data in and out 
> under the kind of load that would require that level of swapping, you'll 
> see that the box will likely die or become completely unresponsive long 
> before you can ever "get there".

What is funny is that I knew this from being told a couple years ago --- 
but out of habit, I still doubled the RAM for swap.. DOH!

> 
> 
> What kind of box is it?  Most "fell off the network and console won't 
> respond locally" types of lockups I've seen over the years are the 
> result of either a piece of hardware acting flakey (usually a bad RAM 
> SIMM/DIMM) or a bug in the kernel drivers for a particular piece of 
> on-board hardware, usually NIC's that don't play nicely.  Have also seen 
> a few broken DMA implementations that would manifest themselves in 
> wicked lockups with nasty data corruption, but that's super-rare and 
> many years ago.

It is a Western Scientific :

  Server Model: WS-2UOPT/3GB (Fusion A64 )
motherboard: Arima HDAMA, Dual 100/1000, 8x Memory Slots
CPU: (2) Opteron 240, 1.4Ghz
System Disk: 80GB 7200 RPM IDE
RAID: 8 @ 200GB 7200 RPM SATA Drives
Memory: 3GB Registered ECC DDR 333, PC2700, 6x 512MB
3-Ware 8506-8, 8-port SATA RAID Card
CDROM


The 3-Ware card model number was not listed on the RH suppported 
hardware list, but another model similar was.

> 
> When the machine stops responding on the network, is the local console 
> still alive?

The console is locked up when it stops responding.



> 
> -- 
> Nate Duehr, nate at natetech.com
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-- 
Michael Belanger
CICLOPS, Space Science Institute

phone. 720-974-5853   Jabber: mrb at jabber.ciclops.org
fax.   720-974-5860

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