SCSI Toolbox :: Newsletter - January 2006
IN THIS EDITION
6.0.10 STB Release currently shipping!
SCSI Compliance testing issues
The role of SCSI diagnostic tools in the iSCSI environment
Ask Dr. SCSI - How do I convert a LBA (Logical Block Address) on my disk drive to the Cylinder/Head/Sector (CHS) of the drive?
6.0.10 SCSItoolbox Suite Now shipping!
The 6.0.10 Release of the SCSItoolbox Suite is currently shipping to Active Performa customers. If you are interested in receiving this 6.0.10 release please contact Sales.
If you haven't received your download information please contact Jeremy Wolfe at jeremyw@scsitoolbox.com or 720.249.2641, please have your STB Serial Number handy.
SCSI Compliance testing issues
SCSI compliance testing really consists of two test steps – step one is to determine if “legal” SCSI CDB's are processed properly, and step two is to determine that “illegal” CDB's fail in the expected way.
The first step is usually accomplished by sending valid CDB's to the device under test. You may want to limit what commands you send, such as not sending a FORMAT command to a disk or an ERASE command to a tape. You could send these commands, you just need to be ready to wait along time for them to complete!
Another choice that can be made with these files is to specify 0 length for all write commands – this tests that the drive can process the command but doesn't actually every write anything to the media. If you are concerned about whether the device can really write and read data reliably you should really use the other tests in the SCSItoolbox to check.
The other choice you need to make is what CDB's are you going to test? When you look at the SCSI specs you'll see that there are MANDITORY and OPTIONAL CDB's for each type of SCSI device. The files included in the SCSI Compliance Test for Scriptwriter Pro include each of the above.
The second step - testing how the device processes illegal commands, is done by sending a series of illegal CDB's to the device.
What is an illegal CDB? This is usually defined as a CDB that has one or more RESERVED bits set. The ScriptWriter Pro sample program allows you to do this testing as well by specifying which bits in the CDB bytes are RESERVED. Included are test data file called ILLEGALDISK.DAT (and tape, and jukebox) to show you how this can work.
This type of testing is useful when device firmware designers are testing to make sure their drives are failing in the proper way.
The role of SCSI diagnostic tools in the iSCSI environment
The role of SCSI diagnostic tools in the iSCSI environment
As iSCSI begins moving from designs to real world products, diagnostic tools are needed for a variety of purposes. This paper will address a few real-world experiences gathered while working in this new environment.
What are the issues?
At the highest level, the question is "is this storage subsystem working?” Does the computer system recognize the disk on the other end of the wire? Is the capacity of the disk readable? Can the inquiry data be shown? Can the disk write and read data reliably?
Once communication is established and verified ... <read complete article here>
Ask Dr. SCSI - How do I convert a LBA (Logical Block Address) on my disk drive to the Cylinder/Head/Sector (CHS) of the drive?
Q. “How do I convert a LBA (Logical Block Address) on my disk drive to the Cylinder/Head/Sector (CHS) of the drive?”
A. On the main screen of SCSItoolbox highlight the drive you want to convert the LBA to CHS. On the top level menu click on "Disk", then "Commands", then "Data Functions", then "Translate Address". You will be presented with a dialog box that has the fields "LBA Address", "Cylinder", "Head", and "Sector". In the "LBA Address" field enter your LBA. On Dr. SCSI's drive I might enter 1735134. Then click the "Translate" button. SCSItoolbox will fill in the " Cylinder","Head", " Sector " fields on the dialog box. In Dr. SCSI's example of LBA = 1735134, the CHS is Cylinder=569, Head = 3, and Sector = 102.
