[nycbug-talk] odd memory issue on

[Pete Wright]

On 10/18/12 12:29, John Baldwin wrote:
> On Thursday, October 18, 2012 2:47:42 pm Pete Wright wrote:
>> On 10/18/12 11:26, Brett Wynkoop wrote:
>>> Greeting-
>>>
>>> I just had a 32 bit system lock up on me with the need to hit the power
>>> switch.  I thought it was odd because I was doing very little on it,
>>> just an mv of some files from one filesystem to another.
>>>
>>> On rebooting I found this interesting bit of info:
>>>
>>> real memory  = 805306368 (768 MB)
>>> avail memory = 238981120 (227 MB)
>>>
>>> This of course leads to:
>>>
>>> ZFS WARNING: Recommended minimum RAM size is 512MB; expect unstable
>>> behavior. ZFS WARNING: Recommended minimum kmem_size is 512MB; expect
>>> unstable behavior. Consider tuning vm.kmem_size and vm.kmem_size_max
>>>                in /boot/loader.conf.
>>>
>>>
>>> Now the $1M question......why in the world is only 227MB available?  I
>>> know I have not stolen all the other memory with stupid bios settings
>>> like giving it to video.
>>>
>>> Ideas or clues appreciated.
>> you check that you don't have any failed DIMM's, or DIMM's about to fail
>> due to ECC issues?
> The real memory thing can lie a bit in modern versions since it is not based
> on a count of actual memory but based on what the SMBIOS tables say about
> the available RAM sticks.  That said, when a DIMM fails I usually see it not
> be reported via SMBIOS either.  Can you do a verbose boot and capture the
> 'SMAP=' lines at the very beginning (you'll have to page up on a VGA console
> or use a serial console, they are output too early to be captured in the
> message buffer dumped by 'dmesg')?  Alternatively, I think there is a 'smap'
> or 'show smap' command in the loader that can dump these from the loader
> prompt (and then you can take a picture).  Those lines will tell you how much
> RAM the BIOS really says is available to the OS as opposed to the sticks that
> SMBIOS says are installed.
>
along similar lines dmidecode(8) may be of help here as well.  it's in 
ports/pkg's.

-p


-- 
Pete Wright
pete at nomadlogic.org
twitter =>  @nomadlogicLA