Re: HEADS UP: New ZFS in the tree.

From: Nikolay Denev <ndenev_at_gmail.com>
Date: Wed, 19 Nov 2008 11:48:17 +0200
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On 19 Nov, 2008, at 11:25 , Larry Rosenman wrote:

> On Wed, 19 Nov 2008, Jeremy Chadwick wrote:
>
>>
>> Since this is CURRENT, you should be able to increase the kmem_size
>> and kmem_size_max entries to something larger than 1536M, especially
>> since the box has 4GB of RAM.  (You shouldn't do this on RELENG_7).
>>
>> You might also consider disabling prefetch; there are reports of
>> peoples' boxes locking up hard (requiring a hard reset) when prefetch
>> is enabled.  Others (like myself) just see "better overall system
>> responsiveness" when prefetch is disabled.
> Just as a note, with a -CURRENT from shortly after the ZFS upgrade,  
> the vm.kmem* tuneables, without ANY override on my 4G amd64 box:
>
> vm.kmem_size_scale: 3
> vm.kmem_size_max: 4509713203
> vm.kmem_size_min: 0
> vm.kmem_size: 1381195776
>
> this is with a 2T zfs array, if that matters.
>
>
> -- 
> Larry Rosenman                     http://www.lerctr.org/~ler
> Phone: +1 512-248-2683                 E-Mail: ler_at_lerctr.org
> US Mail: 430 Valona Loop, Round Rock, TX 78681-3893

Well, it looks like that on -current and a 4G amd64 machine probably  
there is no need
to tune anything. Here are my defaults with everything vm and zfs  
related in loader.conf commented :

vm.kmem_size_max: 4509713203
vfs.zfs.arc_max: 863907840


- --
Regards,
Nikolay Denev




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Received on Wed Nov 19 2008 - 08:48:24 UTC

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