[geeks] One, two, three, panic!

[Shannon Hendrix]

On Mar 16, 2009, at 01:51 , Jonathan C. Patschke wrote:

> On Sun, 15 Mar 2009, Phil Stracchino wrote:
>
>> But this time I saw it.  Reinstalled 7.1R-i386, remirrored boot,  
>> set up
>> a zpool on the 9500, put /usr/ports onto it, tried to do an  
>> updatedb for
>> locate, and FreeBSD fell over instantly:
>
> Did you tune your kernel prior to setting up the zpool?  ZFS on
> FreeBSD/i386 is extremely panic-prone if you don't tune first  
> because of
> the massive amount of kernel memory it can ask for on short notice.
> FreeBSD/i386 tends to keep the kernel footprint slim because of the
> architectural limits of the i386 memory map.
>
> Specifically, you'll want at least these tunables in /boot/ 
> loader.conf:
>  vfs.zfs.arc_min="32M"
>  vfs.zfs.arc_max="256M"
>  vfs.zfs.prefetch_disable=1

The primary of these and other ZFS memory parameters is change  
performance, correct?

I would actually be willing to occasionally have lower performance on  
Solaris in exchange for lower memory usage on my Solaris 10 box, so I  
might see if you can tune it there too.

It's usually not too bad, but can get pretty excessive at times.

It's actually puzzling why ZFS needs to much memory, even after  
reading some explanations.



-- 
Shannon Hendrix
shannon at widomaker.com