BSD Not detecting DIMM

jspsandhu · 06-25-2006, 02:16 PM

Have you ever heard of this that FreeBSD is unable to detect the RAM on an Intel 2u Chassis.
I am facing this problem with FreeBSD Version 4.2 I cannot install and test any other version
I have tested the RAM on an IBM Unit and there on a Linux Redhat I get all the four DIMMS detected but on the OS 4.2 freeBSD I am unable to get thos detected

Any Help.....

Regards

jspsandhu · 06-25-2006, 02:17 PM

Just to clear things there are 4 DIMMS and 3 gets detected on FreeBSD 4.2 and the last 1GB ram is not detected.

jspsandhu · 06-28-2006, 02:35 PM

I Hope no one is in a mood to help in terms of FreeBSD

Well nyways

Still if someone has some info do port

Regards,

btmiller · 06-29-2006, 01:12 AM

Operating systems don't detect individual DIMMs -- they rely on the BIOS and other probing mechanisms to determins the system memory layout. Is the BIOS reporting the correct amount of memory on POST? It's possible the DIMM slot on the motherboard is bad.

BTW FreeBSD 4.2 is extremely old -- why can't you test anything newer, just out of curiousity (I doubt this is your problem, though)?

jspsandhu · 06-29-2006, 09:03 AM

The BIOS does detect them fine and that is why I said that the OS is not detecting the memory
The output on the command dmesg for real memory and avail memory shows me that it is 3 GB and I was just checking the manual for these server and three others and they all showed 3 GB of memory So i got curious at night when there is minimum traffic I opening the Chassis of one of the server shows 4 DIMMS 1 GB each...

Regards,

btmiller · 06-30-2006, 09:57 PM

Are you using a 32 bit or 64 bit distro? 32 bit programs can only access 4 GB of memory and some amount of space is reserved for the kernel plus memory mapped I/O in the motherboard chipset. So you only see 3 - 3.5 GB of memory even if you have 4 installed. You need a 64 bit kernel + some tweaks to the BIOS to move the moemory mapped I/O area above the 4 GB barrier to fix this.