[Tfug] Re: Server Components

[Harry McGregor]

On Tue, 2003-12-23 at 15:21, Robert J Hunter wrote:
> Hi.  I have been eavesdropping on this list for a month or so, and
> I just wanted to say hello (!) and make some comments about hardware.

Welcome, good to hear from new people around here.

> 1) Tyan MPX w/ dual Athlon MP
> 
> We have about fifty of these systems at work (ranging from 1600+ to
> 2200+ CPUs) in a "beowulf" setup.  Overall I am pleased with these
> systems, but a couple issues we have had with them are:
> 
>   i) These boards run hot and won't be happy unless they live in a
>   well-designed case, air-conditioned room, and have working CPU fans.
>   We have had mixed success using the lm-sensors software to monitor
>   case-temperature and fan-speed.

Good cooling, and boxed cpus, if you are buy new high end procs (the
1200s don't come in retail boxed), as when the fan dies, the proc dies. 
Air conditioning helps, and 120mm fans in a 4U rackmount helps.  I would
NEVER do a 1U dualy.

I have one 1800+ on RMA right now.

Dual athlon is a lot of heat, though the 1200MHz is not that much.

>   ii) Although these boards are supposed to take up to 3GB RAM (ECC),
>   we have had chronic problems with the "high-memory" units (512MB X

Strange we have several systems with high-memory, one being 2x512+2x1GB
without issues.  Another at my office (Windows based) is 3x1GB, and
running fine.  We do extensive memtest86 runs on it before putting it
into production use.

>   4). The units configured with a single 512MB stick are far more
>   reliable.
> 
> 2) RAID
> 
> My advice is to skip the software RAID and get a 3ware controller
> instead. Software RAID is slow and not very robust.

While I love 3ware cards (we have over 4TB of storage on them at the
office), I don't find software raid 1 slow.

Here are some speed tests on a dual athlon rig with software raid1:

zappa:~# hdparm -tT /dev/hda

/dev/hda:
 Timing buffer-cache reads:   992 MB in  2.00 seconds = 496.00 MB/sec
 Timing buffered disk reads:  124 MB in  3.01 seconds =  41.20 MB/sec
zappa:~# hdparm -tT /dev/hdc

/dev/hdc:
 Timing buffer-cache reads:   1008 MB in  2.00 seconds = 504.00 MB/sec
 Timing buffered disk reads:  126 MB in  3.02 seconds =  41.72 MB/sec
zappa:~# hdparm -tT /dev/md0

/dev/md0:
 Timing buffer-cache reads:   1016 MB in  2.00 seconds = 508.00 MB/sec
 Timing buffered disk reads:  118 MB in  3.02 seconds =  39.07 MB/sec

I don't recommend software raid over hardware raid, but I do recommend
software raid over no raid.

A $1K budget does not include room for a good 3ware card.  HighPoint,
Promise, etc don't count if they are not at least $150+ (ok, HighPoint
does not count no matter the price).

			Harry

> Good luck with your project!
> 
> -Rob


--
Harry McGregor, CEO, Co-Founder
Hmcgregor at osef.org, (520) 661-7875 (CELL)
Open Source Education Foundation, http://www.osef.org
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