On Aug 7,  8:59pm, Bill Studenmund wrote:
} Subject: Re: disklabeling a 5 TB partition!?
} > 2.  If you run a filesystem on a raid 5 system using the raw partition, y=
} ou
} > might or might not be able to get more  space, but if you do that, you
} > won't be able to do things like recalculate parity while the filesystem is
} > mounted.   Given the time it takes to calculate parity on something that
} > large, this is probably a trade off you're not going to want to make.  At
} > least, I wasn't willing to make it.
} 
} Huh? How does the partition type being used impact the RAID system's=20
} ability (or inability) to calculate parity?
} 
} Yes, parity on a multi-TB volume is a big (and irritating) deal. But I=20
}	 don't see how partitioning or the lack there of will impact it.
	Perhaps things have changed since last I tried, but as I remember,
when I had a filesystem on /dev/raid0d of a raid5 set some years ago under
NetBSD-1.5 and 1.6/i386, I couldn't run raidctl -P on that mounted
filesystem because the system complained that the device was busy.  Also,
if I started the raid check before the filesystem was mounted, mount would
complain that the device was busy until after the parity calculation was
completed.
	I concluded that in order to do background parity checks, I had to put
filesystems on raid sets on partitions other than the raw partition.  If
this is wrong, then please correct me and let me know what I did in error.
-Brian