speed of a ciss-based pseudo-disk

[Paul Saab]

Mikhail Teterin wrote:
> Hello!
> 
> I have two U320 SCSI drives in a RAID-0 combination attached to HP's
> Smart Array 642. This is the dmesg:
> 
> ciss0: <HP Smart Array 642> port 0xb800-0xb8ff mem 
> 0xfea80000-0xfeabffff,0xfeafe000-0xfeafffff irq 29 at device 1.0 on pci4
> da0 at ciss0 bus 0 target 0 lun 0
> da0: <COMPAQ RAID 0  VOLUME OK> Fixed Direct Access SCSI-0 device 
> da0: 135.168MB/s transfers
> da0: 69419MB (142171680 512 byte sectors: 255H 32S/T 17423C)
> 
> Why is the reported speed only 135.168MB/s? All equipment is U320, so
> I'd expect the nominal speed of 320MB/s...

Because it is a bogus number.  There's no way to query for this.  You're 
running at full speed.

> Also, what, if anything, are people using to monitor/control ciss-based
> arrays? HP offers software, but only for Linux and Windows...

HP has not released their acu, so you're limited to what the driver 
reports in syslog.