Date: Tue, 22 Mar 2016 18:20:18 +1100 From: Peter Jeremy <peter@rulingia.com> To: Hal Murray <hmurray@megapathdsl.net> Cc: freebsd-arm@freebsd.org Subject: Re: Effect of partitioning on wear-leveling Message-ID: <20160322072018.GF64087@server.rulingia.com> In-Reply-To: <20160322064502.C7FA9406061@ip-64-139-1-69.sjc.megapath.net> References: <peter@rulingia.com> <20160322062635.GD64087@server.rulingia.com> <20160322064502.C7FA9406061@ip-64-139-1-69.sjc.megapath.net>
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--tMbDGjvJuJijemkf Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2016-Mar-21 23:45:02 -0700, Hal Murray <hmurray@megapathdsl.net> wrote: >Has anybody worked out the numbers for something like writing 100 bytes to= a=20 >log file and flushing things? I think that turns into 2 page writes, one = for=20 >the data and one for the directory info. I assume you mean something like write(2) then fsync(2). If you're talking UFS, it's at least 2 synchronous writes (more if you need to grow the file across a block boundary). There's also an asynchronous update to the timestamp in the first superblock. ZFS is radically different and I'm not sure how many blocks wind up being written - but around 10 plus 4 per device in the pool seems likely. --=20 Peter Jeremy --tMbDGjvJuJijemkf Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQJ8BAEBCgBmBQJW8PIyXxSAAAAAAC4AKGlzc3Vlci1mcHJAbm90YXRpb25zLm9w ZW5wZ3AuZmlmdGhob3JzZW1hbi5uZXRFRUIyOTg2QzMwNjcxRTc0RTY1QzIyN0Ux NkE1OTdBMEU0QTIwQjM0AAoJEBall6Dkogs0yjMQAJMt2ucNxgwoyrFdX3u33gnc Q/bFqzHf9M9eyRyA9g0DL9mvVGwR5RxYCVL8/Q7Nfq3WZxevOto1hSO/P6JpxZ9/ FHDogMEPbpt468q93/oi4O5qs3YX0HkfBT3T1k2iArAmUxtSQHRa2qpQmy5w8dIU UsKDimX2TZFd+K5ACF29DYCiKafMQ/t36p0uIPTDOn/fp2WhDG+KCGRlK8UHGrRz Y4Shaq1nDFpvJ5CFX7sOCMAy3kCIh6CHzk/n84P9cadgrqJ4++q/55MraayQvzTH A4dE9n3CiOVqY+0e6qlw0+PQV1Nax+OQ5TNd9t+ZXPehuDCuIBlqj+vB+ji5Kw2y 479Xbk7aHws6I1Z/FZvSSr5j107qJ05LKdt7clmAKGRgEorwbgNJU1D7VfruuOPx MeeuXeSJOcDOcq0WGInvWghKQfzny+jT6sGERqyoukomMIQZaKushKC0uiHFfYFH GMpWHWDxefAR8loVkoPDl0z0wehsftRyDltRHZ45V8a6O725+ua2xYuCUmaNACcA o1s/wfma21T8rwBj/d28umYuQM3N+mF+aoazSBu60u+wm8WS/vM/r8oJhelDsYYg +xKiE4aLuqCn+jMwhq6BeoFvFJv0TaHBM9vLHojHE9MxRSis4Kpscw7UPmmjK+bg 5SWjF1fShsUzQKpRHqqs =CQ7v -----END PGP SIGNATURE----- --tMbDGjvJuJijemkf--
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