20040615: Quick update on weather3.admin.niu.edu... (cont.)

>From: Gilbert Sebenste <address@hidden>
>Organization:  NIU
>Keywords:  200406150354.i5F3sOtK011267 LDM Fedora Core Linux

Hi Gilbert,

re: When did you upgrade to the *.2190.nptlsmp kernel?

>Last week, in utter deperation, when it was still doing it under 2188.

OK, this is important information.

>I am wondering if what Gerry said is correct. Take a look at my 
>"partitions". Those are the default, and I'm realizing that may be my 
>mistake.

What Gerry was really talking about was keeping the LDM queue off of a
RAID partition.  I have been working with Gerry to get his machine
running well under FC1 with a RAID.  My experince with RAID under Linux
has not been a good one.  After my experience in trying to use a
hardware RAID card (Promise FasTrak TX2000) I switched to use of
softare RAID setup by the FC1 installation program.

When Gerry experienced performance problems on his dual Xeon 2.4 Ghz
box, I suggested that he try a software RAID AND move his LDM queue off
of his RAID and onto his system disk (this is how I have setup two
machines).  After he got his /etc/raidtab entries tuned, his machine
started running nicely.

-- Aside: the FC1 Linux SMP kernels recognize and use the
hyperthreading offered by the Xeon processors.  Gerry's dual CPU
machine looks and performs like a quad processor machine.  His load
averages are at or below 1 for the great majority of the time even
though he is ingesting ALL data available in the IDD AND decoding all
CONDUIT and other data into GEMPAK format AND filing all NEXRAD Level
II data!  Neither Gerry or the UPCs machines have crashed with buss
errors or any other reason.

>Take a look at my partitions on weather, which are localized. 

As far as I can tell, weather3 does not have a RAID:

cat /etc/fstab
LABEL=/                 /                       ext3    defaults        1 1
LABEL=/boot             /boot                   ext3    defaults        1 2
none                    /dev/pts                devpts  gid=5,mode=620  0 0
none                    /proc                   proc    defaults        0 0
none                    /dev/shm                tmpfs   defaults        0 0
/dev/hda3               swap                    swap    defaults        0 0
/dev/fd0                /mnt/floppy             auto    noauto,owner,kudzu 0 0
/dev/cdrom              /mnt/cdrom              udf,iso9660 
noauto,owner,kudzu,ro 0 0

df -k
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/hda2            238172636  43623996 182450092  20% /
/dev/hda1               202220     25097    166683  14% /boot
none                    774692         0    774692   0% /dev/shm

Looks to me like this has 1 250 GB hard disk.  Am I missing anything?

>Yep, no problems there, AND I have a 400 MB queue.

My experience says that the queue size should not be a problem.  Again,
I am running under FC1 with LDM queues ranging from 1 to 4 GB.  If
making the queue small helps, it may well be the case that you have
some sort of a problem with memory (the LDM queue is a memory mapped
file).  What memory do you have installed in weatehr3?

>I was going to install 
>FC2 after they get some crucial bugs out (like cups not working for my 
>printer, Nvidia driver mega-problems).

We tried building the LDM with large queue support (> 2 GB)
on a test FC2 machine here yesterday.  The test failed miserably.
I strongly recommend that you not upgrade to FC2 at the moment!

>I suspect it isn't this new kernel. It's my partitions.

I am not sure how this would be the case, since I do not see you using
a RAID.

Cheers,

Tom
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