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Re: [zfs-discuss] zfs on 32 bit?

Subject: Re: [zfs-discuss] zfs on 32 bit?
From: Erik Trimble
Date: Sun, 14 Jun 2009 15:54:33 -0700
Jürgen Keil wrote:
besides performance aspects, what`s the con`s of
running zfs on 32 bit ?

The default 32 bit kernel can cache a limited amount of data
(< 512MB) - unless you lower the "kernelbase" parameter.
In the end the small cache size on 32 bit explains the inferior
performance compared to the 64 bit kernel.
It's been a long time, but I seem to recall that the ZFS internals were written using values (ints, longs, etc) as found on 64-bit architectures, and that there was the possibility that many of them wouldn't operate properly in a 32-bit environment (i.e. size assumption mismatches on values that might silently drop/truncate or screw up calculations). I don't know if that's still correct (or if I'm getting it completely wrong), but the word was (2 years ago), that 32-bit ZFS might not just have performance problems, but might possibly be silently screwing you.

--
Erik Trimble
Java System Support
Mailstop:  usca22-123
Phone:  x17195
Santa Clara, CA
Timezone: US/Pacific (GMT-0800)


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