Re: GBDE performance on ZIP disks
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 pgp0.pgp Description: PGP signature
GBDE performance on ZIP disks
Hi, is there a way to speed up writing to a gbde encrypted ZIP disk? Copying 37 MB of data to an encrypted disk (in a SCSI drive) that has been initialized with newfs -O 2 -U /dev/da1a.bde takes ~180 seconds, which is ~200KB/s. Copying the same amount of data to the disk without using gbde takes ~50 seconds, which is ~740KB/s. I guess this problem is similar to the one you have when using msdosfs on a SCSI ZIP drive, which is also very slow. Using a different sector size than the default 512, which is also the sector size of the media, doesn't seem to be possible and always results in a gbde: write sector 0: Operation not permitted. Playing around with newfs's options didn't help so far, either. Stefan pgp0.pgp Description: PGP signature
Re: GBDE performance on ZIP disks
On Mon, 27 Oct 2003, Stefan Walter wrote: is there a way to speed up writing to a gbde encrypted ZIP disk? Copying 37 MB of data to an encrypted disk (in a SCSI drive) that has been initialized with newfs -O 2 -U /dev/da1a.bde takes ~180 seconds, which is ~200KB/s. Copying the same amount of data to the disk without using gbde takes ~50 seconds, which is ~740KB/s. I guess this problem is similar to the one you have when using msdosfs on a SCSI ZIP drive, which is also very slow. Using a different sector size than the default 512, which is also the sector size of the media, doesn't seem to be possible and always results in a gbde: write sector 0: Operation not permitted. Playing around with newfs's options didn't help so far, either. 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 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... Robert N M Watson FreeBSD Core Team, TrustedBSD Projects [EMAIL PROTECTED] Network Associates Laboratories ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to [EMAIL PROTECTED]
