topic Re: DVD performance in Operating System - HP-UX

DVD performance

Joao Rei — Thu, 05 Jun 2008 12:04:48 GMT

Hi,

My system is rx6600 11.31.

The read performance of the DVD is very low.

time dd if=/dev/mycdrom of=/dev/null bs=1024k count=100
100+0 records in
100+0 records out

real 4:19.6
user 0.0
sys 20.2

/dev/mycdrom is a link to
/dev/deviceFileSystem/Usb/MassStorage/dsk/disk@hp-1008+294=A60020000001

It will take 3 hours to read the entire DVD with dd.

Is there any performance tool to analyze the DVD IO?

As anyone experienced bad DVD performance on 11.31?

Regards,

Joao Rei

Re: DVD performance

Jaime Bolanos Rojas. — Thu, 05 Jun 2008 12:10:34 GMT

Joao,

Is that a USB DVD? if that is so, then yes there are performance issues with it in 11.31.
HP is working on it and itÂ´s re-writing the drivers so it works better.

Regards,

Jaime.

Re: DVD performance

Duncan Edmonstone — Thu, 05 Jun 2008 13:22:48 GMT

The rx6600 DVD drive is USB attached. There are some key changes to USB planned in the Sep 09 release of 11iv3, that may address performance amongst other things.

HTH

Duncan

Re: DVD performance

TwoProc — Thu, 05 Jun 2008 17:20:00 GMT

Try reading from from the "rdsk" path instead of the "dsk" path.

So reading the device at:
/dev/deviceFileSystem/Usb/MassStorage/dsk/disk@hp-1008+294=A60020000001
would change to :
/dev/deviceFileSystem/Usb/MassStorage/rdsk/disk@hp-1008+294=A60020000001

In prior operating systems of HPUX, this usually makes a huge difference in doing a dd from a disk device.