On 24.07.2012, Heinz Diehl wrote: [....] And that's obviously not all. The problem occurs also with _unencrypted_ partitions/devices, here's the proof (/dev/sda1 is a 500M ext2 partition mounted on /boot; using the same Hitachi rotational drive as in my previous test): [root@wildsau /]# blockdev --setra 8192 /dev/sda1 [root@wildsau /]# hdparm -t /dev/sda1 Timing buffered disk reads: 236 MB in 3.00 seconds = 78.57 MB/sec [root@wildsau /]# blockdev --setra 0 /dev/sda1 [root@wildsau /]# hdparm -t /dev/sda1 Timing buffered disk reads: 26 MB in 3.05 seconds = 8.51 MB/sec [root@wildsau /]# blockdev --setra 0 /dev/sda1 [root@wildsau /]# hdparm --direct -t /dev/sda1 Timing O_DIRECT disk reads: 236 MB in 3.02 seconds = 78.09 MB/sec All this is on F17, with a vanilla 3.5 kernel from kernel.org (with just 3 own small patches wich do not touch code involved here). _______________________________________________ dm-crypt mailing list dm-crypt@xxxxxxxx http://www.saout.de/mailman/listinfo/dm-crypt
