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] [EMAIL PROTECTED]> 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] [EMAIL PROTECTED]> 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] [EMAIL PROTECTED]> 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] [EMAIL PROTECTED]> 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
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