Anyone using Intel Xeon 64 bit servers?

[Murray Hunter <mh...@jaydeonlineinc.com>]

We are trying to set up and test Nutch on a dual Xeon 64 server running the following:
OS: 2.6.9-5.0.3.ELsmp (buildcentos@x8664-build) (gcc version 3.4.3 20041212 (Red Hat 3.4.3-9.EL4)) 
Ram: 8 GB
Disks: 730 GB usable SATA Raid array
JDK emt64: Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_03-b07)
          Java HotSpot(TM) 64-Bit Server VM (build 1.5.0_03-b07, mixed mode)

We had previously set it up on a 32 bit machine and ran into no problems.  We had run a load test on the 32 bit server and got some pretty good numbers and even with large search loads the linux system load average only reached 2 to 3.

On the 64 bit server after we run the first load test with only 5 searches / sec. for a while it suddenly starts having issues and the linux system load average starts getting huge and has jumped to as high as 55 and 122 causing the system to essentially freeze and require a reboot.

We have tried a few other tests indepedent of Tomcat and Nutch and it seems there may possibly be some kind of 4 GB i/o limit with Java.  We will be doing more testing later today.   

I have seen on the list where people were running 64 bit opterons and didn't seem to have a problem, so I wanted to see if anyone else had tried running it on a 64 bit Xeon server, and if anyone else had put in more than 4 GB of Ram with a 64 bit system.

Thanks,

Murray Hunter
JaydeOnline Inc.