Date: Tue, 28 Oct 2003 14:31:46 +0100 From: Stefan Walter <sw@gegenunendlich.de> To: Robert Watson <rwatson@FreeBSD.org> Cc: current@FreeBSD.org Subject: Re: GBDE performance on ZIP disks Message-ID: <20031028133146.GA954@kyuzo.dunkelkammer.void> In-Reply-To: <Pine.NEB.3.96L.1031027212114.99244E-100000@fledge.watson.org> References: <20031027125318.GB1582@kyuzo.dunkelkammer.void> <Pine.NEB.3.96L.1031027212114.99244E-100000@fledge.watson.org>
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--gKMricLos+KVdGMg Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Robert Watson, 28.10.03, 03:26h CET: [...slow gbde encrypted ZIP disk...] > How do things look performance-wise if you do a raw sector read comparison > with dd at various blocksizes? My recollection is that our msdos code Here are a few numbers (for reading - the ones for writing don't really differ): [13:45] stefan@kyuzo> sudo dd if=/dev/da1 of=/dev/null bs=512 count=1000 1000+0 records in 1000+0 records out 512000 bytes transferred in 20.559991 secs (24903 bytes/sec) [13:45] stefan@kyuzo> sudo dd if=/dev/da1 of=/dev/null bs=8192 count=1000 1000+0 records in 1000+0 records out 8192000 bytes transferred in 25.996819 secs (315115 bytes/sec) [13:46] stefan@kyuzo> sudo dd if=/dev/da1 of=/dev/null bs=32768 count=1000 1000+0 records in 1000+0 records out 32768000 bytes transferred in 46.302189 secs (707699 bytes/sec) [13:47] stefan@kyuzo> sudo dd if=/dev/da1 of=/dev/null bs=65536 count=1000 1000+0 records in 1000+0 records out 65536000 bytes transferred in 77.230242 secs (848579 bytes/sec) > would benefit hugely from the addition of clustering support, but UFS2 > with a fragment size matching GBDE's notion shouldn't present the same > problem... The fragment size practically doesn't matter; I tried newfs's defaults (block size 16384, frag size 2048) as well as a fragment size matching gbde's sector size (-> block size 4096, frag size 512), and the time difference for copying the mentioned 37 MB of data was <1 second. Stefan --gKMricLos+KVdGMg Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.3 (FreeBSD) iQGVAwUBP55vwlaRERsSueCzAQKPswwAnuI4TuatOQUAG5zgWDuu+dlCSCrc8pJX zMllzhjlSG8Ycmn3g2RC0Y9XXSak6uMFh+BVfwjD6qY77b/bj+NFUC3G1iCHiSBD bGup6WS9Fsgo7sU6y6fRh8ms2zkUva3Bx0/hUbe6Ko2tuklzk3mhZrPZxI1Aj9Rj BRPY7VYnNv473UEvJRGQ3uCPR02iSEDuR9qzE7fhl4OxDF6KJ46snZ513dsf02/E iIwC/nL6nxRoClTPjgF0WI42gl7rEf4Of1nm62XzgbeRozlzt7te417LIRmn6+Ua 0CgZKE5L22u7o715s7GQXJdATDQRruZ/e80Targes+dKwTy2Qx0sMgeZ92AfqROI mfZfpPzfh6xoDMS1js5zWPClUhvNj5YuxAHWQYHeCDuZ2J3eVRK3dN0x3NogwiOY M6tHfaapUlJw3JROIPuEexpcnxeotL/iXBkzNB2vfME5MhJGRlSi/aozw3eCcXyU CHoIITLtM4/+o6XP/qga86SNasYhz7ep =CnGH -----END PGP SIGNATURE----- --gKMricLos+KVdGMg--
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