I am issuing 512 Kbyte reads through the device mapper device node to a fibre channel disk. With 2.6.30 one read command for the entire 512 Kbyte length is placed on the wire. With 2.6.31 this is being broken up into 5 smaller read commands placed on the wire, decreasing performance. This is especially penalizing on some disks where we have prefetch turned off via the scsi mode page. Is there any easy way (through configuration or sysfs) to restore the single read per i/o behavior that I used to get? -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
