Messages in this thread | | | Date | Mon, 24 Mar 2008 23:19:28 +0100 (CET) | From | Jan Engelhardt <> | Subject | strange crypto speeds, sort of |
| |
Hi,
How come reading a file from a filesystem on an encrypted block device is faster than reading the encrypted block device itself?
Linux home 2.6.23.17-rt #1 SMP PREEMPT RT 2007/10/26 14:17:15 UTC i686 athlon i386 GNU/Linux cryptsetup 1.0.5
/home # echo 3 >/proc/sys/vm/drop_caches /home # dd_rescue foo /dev/null ... Summary for foo -> /dev/null: dd_rescue: (warning): /dev/null (120704.0k): Invalid argument! dd_rescue: (info): ipos: 120704.0k, opos: 120704.0k, xferd: 120704.0k errs: 0, errxfer: 0.0k, succxfer: 120704.0k +curr.rate: 8728kB/s, avg.rate: 13482kB/s, avg.load: 7.1%
/home # echo 3 >/proc/sys/vm/drop_caches /home # dd_rescue /dev/mapper/home /dev/null ... Summary for /dev/mapper/home -> /dev/null: dd_rescue: (info): ipos: 21504.0k, opos: 21504.0k, xferd: 21504.0k errs: 0, errxfer: 0.0k, succxfer: 21504.0k +curr.rate: 4291kB/s, avg.rate: 4291kB/s, avg.load: 5.8%
| |