Kris Kennaway wrote:

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> No, clearly it is not enough=20

This looks like we're constantly chasing the "right amount". Does it=20
depend so much on CPU and IO speed that there's never a generally=20
sufficient "right amount"? So when CPU and drive speed increase, the new =

amount will always be some bigger value?

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>(and you claimed previously to have done=20
> more tuning than this).=20

Where? What else is there except kmem tuning (including KVA_PAGES)? IIRC =

Pawel said all other suggested tunings don't do much.

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> I have it set to 600MB on the i386 system with=20
> a 1.5GB KVA.  Both were necessary.

My point is that the fact that such things are necessary (1.5 GB KVA os=20
a lot on i386) mean that there are serious problems which aren't getting =

fixed since ZFS was imported (that's over 6 months ago).

I see you've added to http://wiki.freebsd.org/ZFSTuningGuide; can you=20
please add the values that work for you to it (especially for KVA_PAGES=20
since the exact kernel configuration line is never spelled out in the=20
document; and say for which hardware are the values known to work)?

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> ZFS already tells you up front that it's experimental code and likely t=
o=20
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> have problems. =20

I know it's experimental, but requiring users to perform so much tuning=20
just to get it work without crashing will mean it will get a bad=20
reputation early on. Do you (or anyone) know what are the reasons for=20
not having vm.kmem_size to 512 MB by default? Better yet, why not=20
increase both vm.kmem_size and KVA_PAGES to (the equivalent of) 640 MB=20
or 768 MB by default for 7.0?

 >Users of 7.0-RELEASE should not have unrealistic
 > expectations.

As I've said at the first post of this thread: I'm interested in if it's =

ever going to be stable for 7.x.