Very slow writing to SATA disk

[Mikhail Teterin]

> Look in smartmontools I provided patches for that, its not rocket  
> science you know...

This attitude -- on top of the API change itself -- is not really encouraging 
for ISVs, you know :-)

> You need to find out what the transfer rates are for the RAW disk, ie  
> by doing a dd from /dev/zero to the disk with a a resonable blocksize  
> say 1M to minimize overhead. Also read speed from disk to /dev/null  
> blocksize 1M would be helpfull.

The read test averaged 62603828 bytes/sec over a minute or so.
The write test is only 6931231 bytes/sec -- about 9 times less.

While dd is running, `systat 1 -vm' reports about 110 ata-interrupts (irq 25) 
per second during the write test, and about 1000 during the read test.

Thanks for your help.

	-mi