Date: Mon, 24 Nov 1997 21:14:21 +1100 From: Bruce Evans <bde@zeta.org.au> To: fs@freebsd.org Subject: ufs slowness Message-ID: <199711241014.VAA09419@godzilla.zeta.org.au>
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ffs (with a block size of 8K and a frag size of 1K) seems to be about twice as slow as ext2fs (with a block size of 4K and a frag size of 4K) for reading small files. This seems to be due to ffs doing lots more seeks. E.g., for `tar cf /dev/null linux-2.1.63' where there are about 50MB of files in the directory, ffs takes about 40 seconds and ext2fs takes about 20 seconds. The extfs partition is on faster tracks but is fuller. Typical output from systat: ext2fs ffs seeks 372 144 xfers 372 145 blks 2751 1395 msps 0.5 4.1 This was on an IDE so `msps' may actually be right (though it may be broken for dma mode). All file systems were mounted async,noatime. 2.5MB/sec exploits about half the disk bandwidth. Bruce
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