Hey guys,
I have been trying for the past several months to get the full throughput
that I'm supposed to be getting from my UDMA-66 hard drives, but - try as I
might - I can only get sustained reads of 19MB/s max. I am using a promise
Ultra66 controller with four 20.4GB U-ATA-66 WD Caviar drives running at
5400rpm in a RAID5 array on Linux2.2.10, on a 350MHz AMD K6-2 machine w/ a
UDMA66 enabled chipset on the motherboard. (each drive with its own
controller (i.e., one on primary, one on secondary, etc))
I have installed the latest hdparm (3.5 I think) utility, and the latest
UDMA patch. Also, I have attempted to enable UDMA66 support by enabling it
manually with "hdparm -X 23 /dev/hda", and receive the following message:
/dev/hda
setting xfermode to 20 (singleword DMA mode4)
hda: drive_cmd: status=0x51 { DriveReady SeekComplete Error }
hda: drive_cmd: error=0x04 { DriveStatusError }
HDIO_DRIVE_CMD failed: I/O error
I get the same message when I try to set any of the DMA modes. What am I
doing wrong? Does Linux even support UDMA-66 yet?
Someone please help.
Sincerely,
-Carlos
P.S. For what it's worth, RAID5 came up great! (thanks to all your help! =)
