Sun StorageTek VolSafe Secure Media
 
Sun StorageTek 9840D Tape Drive
 
Sun StorageTek T10000A Tape Drive
 
Sun StorageTek T10000B Tape Drive
 
Sun StorageTek 9840 Tape Drive
 
Sun StorageTek 9840B Tape Drive
 
Sun StorageTek 9940B Tape Drive
 
Sun StorageTek 9940 Tape Drive
 

PLA-Support>Sun Systems>TAPE>Tape Hardware>SN-TP: STK T-Series Drive
 

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Goal

Answers to Frequently Asked Questions concerning VolSafe on 9x40 and T10000 Tape Drives.

Fix

Answers to Questions:
VOLSAFE FAQ
=============

How do I enable the Volsafe feature ?

Volsafe is activated via the drive Configuration Menu.

How can I tell if the drive is Volsafe enabled?

The configuration menu will display "Volsafe Y".
SCSI Inquiry byte 55 bit 2 is used to indicate that drive is volsafe enabled.
The ESCON Perform Subsystem Function (PSF) command for Read Subsystem Data byte 15 bit 0 indicates drive is volsafe enabled.


How can I tell Volsafe tapes from Normal tapes ?

Volsafe Media differs from Normal Media in 4 ways:

Visibly -  The Volsafe cartridge labels are bright yellow, the Write Protect Switch is bright yellow.
Physically - The Volsafe cartridge has a unique depression (hole) on the bottom that is detected by sensor(s) in the drive. Normal tapes have no recessed holes on the bottom of the cartridge.
Software - The MIR (Media Information Record) written at the front of the tape contains a specific Volsafe identifier pattern.
Hardware - A non-write-protected Volsafe cartridge loaded in a Volsafe-enabled drive will display "Ready A" once the cartridge is loaded and ready (instead of "Ready U").

How can I tell that I have a Volsafe tape loaded in my drive ?

A non-write-protected Volsafe cartridge loaded in a Volsafe-enabled drive will display "Ready A" (not "Ready U") once the cartridge is loaded and ready.
A Volsafe Tape loaded in a NORMAL (non-Volsafe-enabled) drive will display "Ready F" (File Protected media), whether the File Protect switch on the Volsafe
cartridge is physically enabled or not. All read and tape postioning functions will work as with normal tape, but no write operations are allowed.

SCSI - Sense Data Byte 24 Bit 1 is used to identify that Volsafe Media is loaded. For example, SCSI Sense Data Byte 24 = 0x12 indicates Data tape, Volsafe Cartridge.
ESCON - PSF command Read Subsystem Data byte 14 bit 0 indicates volsafe tape is loaded.

Can I still run Normal tapes in my Volsafe drive ?

Enabling the Volsafe feature on a drive does not interfere with the operation of non-Volsafe tapes. Normal media will function normally in a Volsafe-enabled drive.


What happens when I load a Volsafe tape in a normal drive?

A Volsafe Tape loaded in a NORMAL (non-Volsafe-enabled) drive will display "Ready F" (File Protected media), whether the File Protect switch on the Volsafe
cartridge is physically enabled or not. All read and tape postioning functions will work as with normal tape, but no write operations are allowed.


Will I need to initialize/format my Volsafe tapes before using them ?

Volsafe Tapes can be ordered pre-initialized, or unlabelled (one TapeMark and an EOD [End-Of-Data]).  Initialized (formatted) Volsafe Tapes will have an 80-byte uncompressed ANSI Standard label matching the volser label on the outside of the cartridge.  The label can be ordered as ASCII or EBCDIC.

NOTE: The ANSI specification recommends that 80 byte records be reserved for leading and trailing labels only. The Volsafe code was designed to be able to overwrite the trailing 80-byte label. This means that you should never write 80-byte uncompressed customer data records.  For example, you can write as many 80-byte uncompressed records as you wish at BOT, but they can be over-written or rewritten UNTIL customer data is added beyond the TapeMark following the label. This means an ANSI-standard-labelled tape can have the 80-byte label at BOT over-written or rewritten, UNTIL customer data is added beyond the TapeMark following the label.  Once DATA is written past the label, the tape is "Volsafed" (protected from over-write) and cannot be rewritten or over-written.

ALSO NOTE: Any non-80-byte record written at the beginning of tape (in place of the 80-byte uncompressed label) is regarded as customer data, and cannot be rewritten or over-written.  For example, if you write a 1024-byte header at BOT to use as a label, this is considered as (non-ANSI-standard for label) customer data, and cannot be rewritten or over-written.


How will I know I'm trying to write over protected data ?

Attempting to over-write previously written customer data on a Volsafe tape will produce the "Write Protect" error message.


How does the drive determine where the end of protected data is on the tape?

The drive uses an "append pointer" to determine the last customer data block written.

The append pointer is defined as the point where there are only 80 byte non-compressed records between the pointer and the EOD. This means that all 80 byte uncompressed records beyond the append pointer can be overwritten.
Therefore, the customer must NEVER write 80 byte uncompressed data records.
80 byte uncompressed records are reserved for header and trailer labels and tapemarks.
The append point is simply the earliest position that you can append write.
You are not required to write at that point. For example:

   
                    . . . . . DATA    TM    DATA    DATA    TM   80bytetrailer  TM  TM  EOD
                                                                  ^            ^
                                                                   |             |
                                                                   |             |
1. If you try to append here                         |              |
   the drive will reject the                                            |
   write command.                                                      |
                                                                                 |
                                         drive append pointer ---   |

    . . . . . DATA  TM  DATA  DATA& Sun StorageTek 9840B Tape Drive




Volsafe, Media, Enable Volsafe, Differences, Volsafe tape load, Normal data tape, Initialize format

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