Re: SATA kernel-buffered read VERY slow (not raid, Promise TX300 card); 2.6.23.1(vanilla)

[Robert Hancock <hancockr@shaw.ca>]

Linda Walsh wrote:
> Robert Hancock wrote:
>> Linda Walsh wrote:
>>> Alan Cox wrote:
>>>>> rate began falling; at 128k block-reads-at-a-time or larger, it 
>>>>> drops below
>>>>> 20MB/s (only on buffered SATA).
>>>> Try disabling NCQ - see if you've got a drive with the 'NCQ = no
>>>> readahead' flaw.
>> http://linux-ata.org/faq.html#ncq
> ---
>    When drive initializes, dmesg says it has NCQ (depth 0/32)
>    Reading the queue_depth under /sys, shows a queuedepth of "1".

Looks like your controller (or at least the Linux driver) doesn't 
actually support NCQ.

>>> 2) Drive Advanced Power Management setting("-B") (write-only):
>>> "HDIO_DRIVE_CMD failed: Input/output error"
>>> 3) Drive Acoustic ("-M"), read = " acoustic      = not supported",
>>> write = " HDIO_DRIVE_CMD:ACOUSTIC failed: Input/output error"
>>
>> Not sure about these ones.. Does anything show up in dmesg when you do 
>> this?
> ---
>    Yes:
>    (for "-B", power-management)
> ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0
> ata1.00: port_status 0x20200000
> ata1.00: cmd ef/05:fe:00:00:00/00:00:00:00:00/40 tag 0 cdb 0x0 data 0
>         res 51/04:fe:00:00:00/00:00:00:00:00/40 Emask 0x1 (device error)
> ata1.00: configured for UDMA/133
> ata1: EH complete
> sd 1:0:0:0: [sdb] 1465149168 512-byte hardware sectors (750156 MB)
> sd 1:0:0:0: [sdb] Write Protect is off
> sd 1:0:0:0: [sdb] Mode Sense: 00 3a 00 00
> sd 1:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't 
> support DPO or FUA
> ----
>   (for "-M" acoustic management):
> ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0
> ata1.00: port_status 0x20200000
> ata1.00: cmd ef/42:fe:00:00:00/00:00:00:00:00/40 tag 0 cdb 0x0 data 0
>         res 51/04:fe:00:00:00/00:00:00:00:00/40 Emask 0x1 (device error)
> ata1.00: configured for UDMA/133
> ata1: EH complete
> sd 1:0:0:0: [sdb] 1465149168 512-byte hardware sectors (750156 MB)
> sd 1:0:0:0: [sdb] Write Protect is off
> sd 1:0:0:0: [sdb] Mode Sense: 00 3a 00 00
> sd 1:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't 
> support DPO or FUA

Looks like the drive reports ERR/ABRT (command aborted), meaning it 
likely doesn't support those commands.

-- 
Robert Hancock      Saskatoon, SK, Canada
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