on 2/13/2008 5:59 AM Alfred von Campe spake the following:
On Feb 12, 2008, at 21:57, William L. Maltby wrote:
Check BIOS settings? For memory, CAS etc. the same? Disk hardware the same and specified identically?
Pretty much all the same. They are standard Lenovo desktops, with a 3.4 GHz Core 2 Duo and 3 GB of memory (the BIOS doesn't let the OS address more than 3 GB).
Presumming that nothing is found there, install system accounting packages and run some SAR reports. You may see a clue in them.
I will try that next.
Any "tweaks" on the old system you forgot to apply on the new? Elevator, buffer flush interval changes, etc?
Nope, it's a vanilla kickstart install. I am using the same scripts (with only slight variations) to build both the 4.x and 5.x systems. I didn't do anything to "tune" the 4.x systems. That's one of the things I like about CentOS (and RHEL for that matter): they just work out of the box. A build (make/gcc) is typically CPU bound. I don't understand how it can get only 11% of the CPU. That's unheard of.
Any other noticeable things on there that may cause it? Presume the slowdown is caused by a process that you are not looking at. "Hangs" while some other process is waiting or tying up the CPU. Try running top.
There is nothing else running on the systems at the time. I have lots of terminal windows open on the 4.x system, but I am ssh'ed into the 5.x system and nobody else is logged in. If anything, the 4.x system should be slower since there are many more things running on it.
I notice an execve shows on the new one that is not in the old. One says "hmmm....".
The execve is in the other as well, just a few lines further down (i.e., it didn't make the cut when I did the "head strace.log").
What does swapon -s show?
CentOS 4.6: Filename Type Size Used Priority /dev/mapper/VolGroup00-LogVol00 partition 4095992 210592 -1
CentOS 5.1: Filename Type Size Used Priority /dev/mapper/VolGroup00-LogVol00 partition 3047416 120 -1
Is the system "seeing" the same amount of memory "available" or have BIOS settings in one reduced available?
CentOS 4.6: MemTotal: 3113612 kB MemFree: 24868 kB Buffers: 23164 kB Cached: 2428508 kB SwapCached: 136108 kB Active: 1685808 kB Inactive: 1257004 kB HighTotal: 2226560 kB HighFree: 1088 kB LowTotal: 887052 kB
CentOS 5.1: MemTotal: 3114452 kB MemFree: 2722528 kB Buffers: 84592 kB Cached: 174804 kB SwapCached: 0 kB Active: 187084 kB Inactive: 137220 kB HighTotal: 2226560 kB HighFree: 1972860 kB LowTotal: 887892 kB
If all new equipment on the new one, open her up and reseat all connections, PCI cards and mem sticks. Make sure all power connectors are well seated to MB and drives.
I will double check that. I may also try to install 4.6 on the HW that is currently running 5.1 and see if there is a problem. With my kickstart scripts I can have the system up and running in less than 30 minutes. That is probably the best next step to rule out any HW issues. I'll do that as soon as I get into the office.
Front side bus and memory speeds set the same in BIOS?
Should be.
That's all I can think of that may be even remotely related ATM
Thanks for all the excellent suggestions, Bill.
Alfred
I didn't see it but did you do a 'uname-a" on both systems to see if one is running a PAE kernel?