Re: iscsi target on a zfs zvol?

[Brian Buhrow <buhrow%nfbcal.org@localhost>]

	hello Brad.  Yes, I've fooled with the block size, cache sizes, a bunch of other
variables.  If you search for slow read/write performance with zvols under FreeBSD or Linux,
you'll find a number of references to this problem, both directly in the openzfs development
bug reports and as bug reports for TrueNAS and other  file server packages.  I've ben
struggling with this speed problem for over a year and a half with ZFS and FreeBSD and when I
finally admitted defeat and began using flat files in zfs filesystems, I discovered the true
magnetude of the problem.  My read/write performance jumped by a factor of 5, which really
astounded me.

-thanks
-Brian

On Jul 16, 10:32pm, Brad Spencer wrote:
} Subject: Re: iscsi target on a zfs zvol?
} Brian Buhrow <buhrow%nfbcal.org@localhost> writes:
} 
} > 	hello.  Yes, I was vaguely aware of the lack of extended attributes for NetBSD-Zfs, but
} > what I was suggesting was just using a flat file, exported via iscsi through istgt or your
} > initiator of choice, on top of zfs, rather than a zvol, because you'll find the read/write speed
} > to be so much faster.  Unfortunately, it seems the upstream zfs maintainers have decided that
} > zvols are not worth the time to optimize, so while they're functional, they're not performant
} > under any openzfs-using implementation.  This makes me sad because zvols are such a tidy way to
} > manage so many different kinds of things.
} >
} > -thanks
} > -Brian
} 
} 
} I freely admit that I don't use zvols very much in NetBSD, but did you
} mess with the volblocksize any on the volume??
}