For the past week I've been trying to figure out why my dm-crypt-on-RAID6 performance is so terrible. To wit: root@yupa:/source# hdparm -t /dev/md1 /dev/md1: <---the RAID 6 block device Timing buffered disk reads: 1262 MB in 3.00 seconds = 420.19 MB/sec root@yupa:/source# hdparm -t /dev/mapper/yupa /dev/mapper/yupa: <---the dm-crypt device with /dev/md1 as the underlying store Timing buffered disk reads: 370 MB in 3.00 seconds = 123.26 MB/sec The machine (a Core 2 Quad) is not anywhere near CPU bound in either case (even with all the bulk encryption), and is obviously not disk bound in the latter. Besides having used linux-2.6.38 and cryptsetup-1.1.3 to build the system, post-hoc analysis of iostat indicates that all layers are properly aligned. My working theory is FSB contention caused by lots of memory copies during the process of moving data through each layer. Has anyone else run into this? _______________________________________________ dm-crypt mailing list dm-crypt@xxxxxxxx http://www.saout.de/mailman/listinfo/dm-crypt
