Re: [uml-user] Kernel virtual memory size shrunk ??

[Net Llama! <net...@li...>]

David Coulson wrote:
> Net Llama! wrote:
> 
>> I'm running a UML instance with the mem=256M option, which i assumed 
>> would
>> provide the UML with 256M of 'physical' memory.  However, as the UML
>> boots, i see this (in dmesg too):
>> Kernel virtual memory size shrunk to 243269632 bytes
> 
> 
> Not got a clue. I've only see that message when I've booted a UML kernel 
> with two .5Gb slots with less than 487Mb of RAM. Of course, since you've 
> got ~240Mb there, and the UML has 249Mb, then you've only got one .5Gb 
> on the go.
> 
> That's one for Jeff though.
> 
>> The host has 4GB of physical memory, so i don't think that's the issue.
> 
> 
> The amount of RAM on the host has no bearing on the amount of memory 
> available to a UML. It is entirly dependent upon the available space 
> within the /tmp filesystem. I can quite happily give a UML 1Gb of RAM on 
> a host with 512Mb, if I have plenty of swap to make up the difference 
> and mount /tmp as a tmpfs filesystem, or have /tmp mounted as a regular 
> ext2/reiserfs/whatever filesystem, although the latter is much slower.

Not sure if this is relevant, but i'm using tmpfs, and for the user 
running the UML instance (trial), i've set TMPDIR to be 
/home/trial/.umltrial directory.  df shows that directory getting used 
when i start the UML.  *shrug*


-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
L. Friedman                       	       net...@li...
Linux Step-by-step & TyGeMo: 		    http://netllama.ipfox.com

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