Device support modifications

z/OS® DFSMS device support provides hardware device-specific code, which allows tape drives, tape volumes, and DASD to interface with z/OS DFSMS. Specifically, it provides:

The interfacing exits to the input/output supervisor (IOS) and EXCP device support code
Error recovery procedure routines
Services to acquire and log statistical and error data
Services to acquire and display device states
Utilities for functions like initializing tapes

You can use the MVS DEVSERV command to request basic status information on a device, a group of devices, or storage control units. You can use the QTAPE parameter of the DEVSERV command to display tape device information. Use DEVSERV QTAPE to display the real device type and the emulated device type.

With the DEVSERV QTAPE MED (medium) option, you can display information for the device type, media type, and cartridge volume serial number.

The syntax of the DEVSERV QTAPE command with the MED option is as follows:

DS QT,xxxx,MED,nnn

xxxx: Represents a three-digit or a four-digit device number in hexadecimal format.
nnn: Stands for the number of devices, starting at the address xxxx, for which the DEVSERV command displays the MED information. The value nnn is optional and can be any decimal number from 1 to 256, with 1 as the default value.

DEVSERV QTAPE will display '3592E06' for the real device type, where E06 is the drive model, if the underlying physical device is a 3592 Model E06 (TS1130). If the MEDIUM option is specified for DEVSERV QTAPE command, the real device type will be displayed as '3592-3E'.

Figure 1 shows the output of DS QT,960 when a TS1130 (3592 Model E06) tape drive emulates a 3590 Model B1x tape drive.

Figure 1. DS QT,960 output

11.20.46 SYSTEM1           DS QT,960                                 
11.20.46 SYSTEM1           IEE459I 11.20.46 DEVSERV QTAPE 760        
UNIT DTYPE  DSTATUS CUTYPE  DEVTYPE  CU-SERIAL  DEV-SERIAL ACL LIBID 
0960 3590   ON-RDY  3592J70 3592E06* 0178-00030 0178-00030

Figure 2 shows the output of DS QT,960,MED when a TS1130 (3592 Model E06) tape drive emulates a 3590 Model B1x tape drive.

Figure 2. DS QT,960,MED output

11.21.21 SYSTEM1           ds qt,960,MED                             
11.21.21 SYSTEM1           IEE459I 11.21.21 DEVSERV QTAPE 763        
UNIT RDTYPE  EDTYPE EXVLSR INVLSR RMEDIA EMEDIA         WWID         
0960 3592-3E 3590-1        1P0694   9      3

A bit DFVTJAG3 is added to the IHADFVT mapping macro that maps the data facilities vector table. When this bit is set, it indicates that all of the software support for the 3592 Model E06 (TS1130) drive is on the system. This bit is set by the enabling module IECTEPTF, if it is installed.

The IECUCBCX mapping macro is changed to support the TS1130:

The new EPI value is X'14' - REALJAG3_EMUL3590
A new data key shred support bit is defined in flag byte 7 (UCBCXFL7) UCBCX_SHRED EQU X'40'

The tape initialization (INITT) and rekeying (REKEY) functions of the IEHINITT Utility now allow an alphanumeric volser to be specified for SER keyword when NUMBTAPE is specified. (Previously, if more than one tape was specified in NUMBTAPE, the volume serial number of the first tape had to be all numeric.) The volume serial number can now be specified as alphanumeric, with the requirement that the last one to six characters be numeric. z/OS will increment the numeric suffix of the volume serial number by one for each additional tape. For example, VOL100 is incremented to VOL101, V19999 is incremented to V20000, and 123456 is incremented to 123457.

The following rules apply when the value specified for NUMBTAPE is greater than 1:

When the numeric suffix exceeds its incremental limit, IEHINITT will process up to the largest number allowed for the numeric suffix and issue a warning message. For example:
```
SER=TOM991, NUMBTAPE=10
```
In this example, the maximum value of the numeric suffix 991 is 999, therefore, up to nine tapes are processed. The tenth tape is ignored and the following new message is issued:
```
IEH641I THE NUMERIC SUFFIX OF THE SERIAL NUMBER EXCEEDED POSSIBLE MAXIMUM VALUE – 
THE LAST VOLUME PROCESSED WAS 'volser' 
```
In this example, the “volser” indicated would be TOM999. An exception to this rule is when the serial number is all numeric and an overflow occurs, the serial number is still allowed to wrap around (Serial number 999999 is incremented to 000000).

When the last character is alphabetic, the following updated message will be issued.

Existing message:
IEH623E INVALID SERIAL NUMBER.  SERIAL NUMBER MUST BE ALL NUMERIC WHEN VALUE 
SPECIFIED FOR NUMBTAPE IS GREATER THAN 1

Changed message:
IEH623E INVALID SERIAL NUMBER. AT LEAST ONE OR MORE RIGHTMOST CHARACTERS MUST 
BE NUMERIC WHEN NUMBTAPE IS GREATER THAN 1

The following parameter keywords for IEHINITT have been updated:

SER=serial number

specifies the volume serial number of the first or only tape to be labeled. Specify up to six characters. For IBM standard labeled (SL) tapes, the serial number cannot contain blanks, commas, apostrophes, equal signs, or special characters other than periods, hyphens, dollar signs, pound signs, and at signs ('@'). ISO/ANSI labeled tapes (AL) may contain any valid ISO/ANSI 'a' type character as described under the OWNER keyword. However, if any non-alphanumeric character (including a period or a hyphen) is present, delimiting apostrophes must be included. You cannot use a blank as the first character in a volume serial number. When NUMBTAPE keyword is specified with a value greater than 1, the volume serial number must be all numeric or the last one to six characters of the volume serial number must be numeric.

When a volume serial number is all numeric, it is increased by one for each additional tape (Note: Serial number 999999 is increased to 000000).

When a volume serial number is alphanumeric, only the numeric suffix is increased by one for each additional tape (Serial number VOL100 is increased to VOL101, T19999 is increased to T20000, and 100A01 is increased to 100A02). In the case where the numeric suffix exceeds its incremental maximum value, IEHINITT processes up to the largest serial number allowed for the numeric suffix and the warning message IEH641I is issued. (For example, SER=TOM991, NUMBTAPE=10 – Up to nine volumes are processed and the last volume is TOM999.)

NUMBTAPE={n|1}

specifies the number of tapes to be processed according to the specifications made in this control statement. The value n represents a number from 1 to 255. If more than one tape is specified, the volume serial number of the first tape must be all numeric or the last one to six characters must be numeric.

The DDR Swap Exit handles swaps involving the 3592 Model E06 drive and the new recording formats EFMT3 and EEFMT3. Appropriate rules are also put in place for handling a lower technology EFMT1, EFMT2, or EEFMT2 request on a 3592 Model E06 to a 3592 Model J or E05 (as appropriate and as consistent with past 3592 support). Table 1 shows a summary of what swaps are allowed.

Table 1. Format swaps allowed for TS1130
Format	From Device	Allowed to device	Notes
EFMT1	3592-J 3592-2 3592-2E	3592-J 3592-2 3592-2E	Swap to a 3592-3E not allowed
EFMT1	3592-3E	3592-J 3592-2 3592-2E 3592-3E	Swap allowed from 3592-3E to any 3592 type device
EFMT1	3592-3E and Write attempted RC-RQC=x’2420’	3592-J 3592-2 3592-2E 3592-3E
EFMT2	3592-2 3592-2E 3592-3E	3592-2 3592-2E 3592-3E	Swap allowed to a 3592-2, 3592-2E or 3592-3E
EEFMT2	3592-2E 3592-3E	3592-2E 3592-3E	Swap allowed to an encryption-capable drive
EFMT3 EEFMT3	3592-3E	3592-3E	Swap allowed only to 3592-3E