Data transfer Rate on MSL 6060

[mohannad]

hi guys,

i have an MSL 6060, LTO4 drives , Fiber connection.

the transfer rate for an LTO drive should be about 240MB/s max.

i noticed something :

in the LCD screen on the library if you navigate through :

View System Data >> SCSI Options >> Data Transfer Speed . you will find that the data transfer speed is 10MB/s

in the manual it says this option is " robot or library SCSI data transfer rate to
Synchronous, 10 MB/sec, Synchronous, 5 MB/sec, or Asynchronous Only. The default is Synchronous, 10 MB/sec."

what dose this mean ??????????
and whats this option??????????

[Uwe Zessin]

It is the SCSI speed to the module which controls the library operation. Those options are intended for operation in 'strange' environments - just keep the default value and you should be fine.

[Timothy Cusson]

You could download HP Library and Tape Tools and run the performance test.

[mohannad]

thanks guys,

i already used the LTT, any thing more specific?

[Rob Leadbeater]

Hi,

What exactly is your issue ?

Can we assume that you're expecting performance near to 240MB/s and that you're not actually achieving that... ?

Cheers,

Rob

[mohannad]

read the case ROB

[Rob Leadbeater]

I did, and it's not clear what your issue is...

You imply that you're not getting the speed you're expecting, but you haven't actually said that...

Cheers,
Rob

[Tom O'Toole]

The problem is the NSR, and you will never get anything close to 240MB/s per drive through it.

I have posted several threads here, if you search for them you can read about the time I have wasted trying. There is also an advisory about this, but the advisory doesn't go far enough, or into enough detail in stating the amount of the degradation in performance.

If you want to run LTO4, get a G3 series with direct fibre attach to the drive - then, and only then, will you see the rated speed.

[mohannad]

guys,

an LTO 4 hotplugable wont give 240 MB , the throughput is bettwen 80 and 160 MB/s this is a fact read the following hp customer advisory "Document ID: c01122518" even on LTT you will see this.

the issue is the following please if you have an MSL 6000 any module you can see this :

in the LCD screen on the library if you navigate through the following menus:

View System Data >> SCSI Options >> Data Transfer Speed . you will find that the data transfer speed is 10MB/s


the question is WHAT IS THIS VALUE, and FOR WHAT DOSE IT REFER TO??????????


in the Manula it SAYS its the : " robot or library SCSI data transfer rate."

the manual is saying this is the SCSI Rate, but thats not correct , Any Idea what this is in specific????????

i think they mean this is the control channel speed for the robotic commands i.e. CDB's.

if anybody knows please advise ?

[Rob Leadbeater]

Hi,

According to the manufacturer's manual:

http://support.overlandstorage.com/jive/servlet/KbServlet/download/6792-102-2251/10400171-101.pdf

Data Speed Transfer:

"Lets you set the SCSI data transfer rate for the library robotics..."

Cheers,

Rob

[Uwe Zessin]

That's what I said ;-)
"the module which controls the library operation"

[Rob Leadbeater]

Indeed !! :-)

[Tom O'Toole · Accepted solution]

All I'm saying is that even a non-hotpluggable lto-4 cannot run full speed via an NSR, and it is not because of a SCSI or fibrechannel bandwidth limitation.

The default synchronous 10MB/s data rate is the only one I have ever seen set on any MSL 5000 or 6000, and I don't think the setting would be a cause of a low data rate to tape drives. You can see both the library and tape drive speed settings in the NSR console "view current map" menu option, I think. It should be 320MB/S for each tape drive, which is plenty (if only the NSR could process it that quickly). Let us know what you find out.