Bob Friesenhahn <bfrie...@simple.dallas.tx.us> wrote:
> On Mon, 13 Jul 2009, Mike Gerdts wrote:
> >
> > FWIW, I hit another bug if I turn off primarycache.
> >
> > http://defect.opensolaris.org/bz/show_bug.cgi?id=10004
> >
> > This causes really abysmal performance - but equally so for repeat runs!
>
> It is quite facinating seeing the huge difference in I/O performance
> from these various reports. The bug you reported seems likely to be
> that without at least a little bit of caching, it is necessary to
> re-request the underlying 128K ZFS block several times as the program
> does numerous smaller I/Os (cpio uses 10240 bytes?) across it.
cpio reads/writes in 8192 byte chunks from the filesystem.
BTW: star by default creates a shared memory based FIFO of 8 MB size and
reads in the biggest possible size that would currently fit into the FIFO.
Jörg
--
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