Gregor's Blog: Greg Matthews Sun Blog

Yes. Need to write a Library Manager (LM) which knows how to control the library and
a Drive Manager (DM) which know hows to use the drive.
If you already have a driver for the optical device, DM can use it to issue commands
to the drive. Otherwise, DM can use USCSI and the sgen driver to do the same.

Posted by Paul Cheng on November 11, 2008 at 01:02 PM CST #

Hi Patrick,

The source code is in opensolaris: http://src.opensolaris.org/source/.
Look in usr/src/cmd/mms and usr/src/lib/mms.

Also, read the docs at http://whitstable-mn.central.sun.com/twiki/bin/view/SMMS/DocumentationCurrent.

MMS used to be called SMMS and the docs have not been changed, so they still refer
to the projects as SMMS.

Can you tell us what the goal of your project is?

Paul.

Posted by Paul Cheng on November 24, 2008 at 09:42 AM CST #

Hi Gregg,

I just start looking at you project. Good luck, its a lot of work. You do need a LM, however, it needs to be more complex than whats alluded to in the IEEE documentation.

In a more generic world, there a may library configurations with more functional objects than a slot, robot, and drive slot. And, the relationships between these actors are more complex. Some robots only have access to a certain range of ports, drives and slots. There can be multiple slot (drive and media)types within the same library, some robots can handle one media, others handle the other media.

You will commonly see drive cleaning cartridges in libraries. BTW, you do have to manage drive cleanings and aging the cleaning media. Drives will stop when there cleaning cycles have been exceeded.

Some libraries may have robot/media paths that can be temporarily blocked. For example, a drive has the media ejected, the robot holding another piece of media does not have the clearance to pass the media ejected from the drive.

The robots also have sensors or cameras that read one or more media or magazine labels (bar codes, rfids and the like). Typically the libraries will give you the raw camera image as well as the cooked/decoded numbers. Some installs mount video cameras in their libraries, I guess "light out" operations still need to see if the library is working.

Media is usually imported and export into a library though one or more ports. Many times the ports only handle magazines of media, not just one tape or disk. Some ports are interconnects from media expansion chassis, which have their own set of robots and are still considered part of the library. Other ports have security features like locks which are under the LM's control.

You would imaging that with a DM and A LM you would know what is going in and out of your libraries... unfortunately, no. Media, magazines, drives, robots,cleaning cartridges and expansion enclosures can change on you by the operator when power is off or the access door is opened. Every time that access door is opened, inventory and configuration is suspect. An inventory usually must be done before any media is move to a slot. Some robots do not detect if media is occupying a slot and will try to insert media into a slot it thinks is free. How many time have you heard, "dude, you meant slot A32? dude, that's where I though I put it".

Additionally, nearly all libraries have an access door, which need to be under LM control or at least the door lock. Nearly all libraries have a automated door lock over-ride. When the access door is opened, it renders the library robots inactive as a safety feature, in fear of broken limbs or death on some of the larger libraries.

Libraries and drives have one or more types of indicators and consoles which range from simple LEDs that blink to alpha numeric displays and simple buttons to full PCs. The LM is responsible for displaying messages to; and receiving key inputs from the operator - passwords are a big issue.

There are multiple types of inventory commands, some read the media (which could take days or weeks to read) another only reads bar code labels (media, magazines, drives)and the other that senses if a media or magazine is in a slot (they try to grab it). Some drives are hot swappable, you need to handle FRU replacement or having a drive pulled during operating -- it does happen.

Also, don't forget about the power supplies, fans, temperature and humidity senors, audible alarms (at least disable them) and library shutdowns due to the sensors going off.

A good model to "start" from is the SNIA (CIM) library profile. Did I mention SNMP and CIMMOM agents ? Another good place to look is the OpenTMS and OpenSMS projects on sourceforge. They were STK products that Steve Cranage convince management to "open source". I believe John Groves in Tx was supporting the projects.

good luck and cheers..

Gary

Posted by Gary Mazz on January 07, 2009 at 11:25 AM CST #