vm.kmem_size settings doesn't affect loader?

Pete French petefrench at ticketswitch.com
Thu Sep 25 15:59:53 UTC 2008

> The ARC uses kmem.  "Should not use that much more memory" is a matter
> of opinion; if an additional 64MB given to ARC causes kmem exhaustion

Well, yes :-) Though I would think if I was runnign a system with 1.5 gig
of kernel memory where an extra 64 meg was the differebce between life
and death then I would be sailing too close to the wind for my liking

> On the bright side, it's very easy to determine how much memory is being
> dedicated to the ARC.  sysctl kstat.zfs.misc will disclose this data
> and I believe the following statistics are the ones you have to examine
> for this issue:

Now this is very useful stuff! I have compared mine to yours, and I am using
more or less an extra 64 meg. which is kind what I expected. I also
tried the script from the wiki page to estimate how much kernel memory
I am using, and that hovers around the 300 meg mark.

> Let's adhere to the K.I.S.S. concept, and not turn this thread into
> a "tuning micro-management" thread.

fair enough - I was just curious about the difference between 64 and 128 on
the ARC cache, and now I have an answer, and more than enough info to do
my own invetsigations as to what works for me. Thanks ;)


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