Re: Playing with SATA NCQ

Michael Thonke
2005-05-29T18:11:13Z

Jens Axboe schrieb:

>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:

cfq: depth 4 reached, tagging now on

This only appears with AHCI enabled what does that mean?

Also a question which options can be set in queue_type?

Best regard and thanks for help

Greets
Michael