On Sun, May 29 2005, Michael Thonke wrote:

Jens Axboe schrieb:

quoted

There's really nothing to be tuned. If NCQ is enabled for your drive, it
will be printed in dmesg after the lba48 flag, such as:

ata1: dev 0 ATA, max UDMA/133, 488281250 sectors lba48 ncq

If you don't see NCQ there, your drive/controller doesn't support it.
Likewise you will have a queueing depth of > 1 if NCQ is enabled, check
/sys/block/sdX/device/queue_depth to see what the configured queueing
depth is for that device.

 

Hello again,

the queue_depth of 30 is okay? On boot the CFQ scheduler tells:

By default, the maximum depth is used. For desktop use, a depth of 2-4
is probably more appropriate until the io schedulers become a little
more intelligent wrt queueing.

      cfq: depth 4 reached, tagging now on

This only appears with AHCI enabled what does that mean?

It only appears if AHCI is enabled, because tagged command queueing is
only working/enabled on AHCI. The message is informational only, CFQ
tells you that it has detected queueing hardware (driver maintains a
depth of >= 4).

Also a question which options can be set in queue_type?

Nothing.

-- 
Jens Axboe