When I'm manipulating over some benchmark tool I/O depth, what exactly am I changing?
Let's say I have SATA disk on /dev/sda. If I run hdparm:
root@linaro-gnome:~# hdparm -I /dev/sda | grep Queue Queue depth: 32 * Native Command Queueing (NCQ)
If I check I/O scheduler queue depth:
root@linaro-gnome:/# cat /sys/block/sda/queue/nr_requests 128
If I check scsi queue depth:
root@linaro-gnome:/sys/bus/scsi/devices/0:0:0:0/block# ls sda root@linaro-gnome:/# cat /sys/bus/scsi/devices/0\:0\:0\:0/queue_depth 31
What am I changing above when manipulating over I/O depth? When someone refers to I/O depth, what is he referring to?
And is there something else I'm missing?