vm.kmem_size settings doesn't affect loader?
bkelly at vadev.org
Fri Sep 26 16:13:54 UTC 2008
On Sep 26, 2008, at 4:43 AM, Bartosz Stec wrote:
> Jeremy Chadwick wrote:
>> These are the tuning settings I use:
> Yesterday I've added 512 MB memory to box (sum 1,5GB), and set
> vm.kmem_size and vm.kmem_size to "1024M". With pieces of 1024MB,
> 512MB, 256MB, 256MB available and 3 memory slots it is hard to have
> 2GB RAM ;)
> Until now it survived world cleaning/building/installing/bonnie++
> benchmarkink/fs scrubing and general usage. Memory usage seems
> stable. If unfortunately kmem exhaustion will happen again I will
> experiment with ARC settings.
> IMHO you've explained gently a lot of zfs tuning concerns in this
> thread and they should be added to tuning guide - espacially
> explanation of ARC and prefetch settings. Thanks again!
Did you increase KVA_PAGES in your kernel config as well?
The default of 256 only allows 1GB of kernel memory total. Setting
KVA_PAGES to 384 would probably be good for a kmem_size of 1GB. This
would give leave you with 512MB of space for other things in the
kernel. In your kernel config:
Sorry if you already knew this. I know its in the zfs tuning guide.
I just hadn't seen it mentioned in the thread yet and wanted to make
sure it wasn't missed.
Hope that helps.
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