Understanding coexistence considerations for encryption-capable TS1120

Coexistence support for the encryption-capable TS1120 tape drive is provided at z/OS V1R4 and above by installing the needed full-support PTFs without the Device Services enabling PTF. However, with the encryption support for z/OS V1R4, V1R5, and V1R8 being delivered after the GA of z/OS V1R6 and V1R7, in some cases, separate coexistence APARs are also available for V1R4, V1R5, and V1R8. In addition to this, existing device services support prevents the encryption-capable TS1120 tape drives from coming online on a system that does not have all of the full-support PTFs installed. Installation of the Devices Services enabling PTF brings in all of the needed full-support PTFs. Device services will provide coexistence support to allow the encryption-capable TS1120 tape drive to come online, but until the full support is installed, it will appear to the host as a 3592-2 without encryption capability. You must install the needed coexistence support on systems that will not have all of the encryption-capable TS1120 tape drive support installed. See Table 1 for a discussion of the coexistence PTFs that may be needed. For past discussion of the 3592 Model J1A and its coexistence considerations, refer to Understanding coexistence considerations for 3592 Model J1A. For past discussion of the 3592 Model E05 and its coexistence considerations, refer to Understanding coexistence considerations for 3592 Model E05.

Review the coexistence migration tasks described in these topics:

Table 1. Coexistence migration tasks for encryption-capable TS1120 tape drives
Environment	Coexistence Considerations
Stand-Alone	As described in Introduction for encryption-capable TS1120 tape drive, z/OS DFSMS and related licensed programs provide full support for the encryption-capable TS1120 tape drive and MEDIA5, MEDIA6, MEDIA7, and MEDIA8 with z/OS V1R4 and above, with support for media types MEDIA9 and MEDIA10 being provided with z/OS V1R5 and above. The encryption-capable TS1120 tape drive support enables the tape drives to operate in the stand-alone environment in 3590 Model B1x emulation and to coexist with other emulated tape drives. However, prior to using the new encryption-capable TS1120 tape drive, ensure that all existing 3592 Model J1A and all existing (base support) 3592 Model E05 tape drives have their microcode upgraded to recognize and enable the EEFMT2 formatted cartridges to be relabelled/reused on the 3592 Model J1A and the base 3592 Model E05. Also, ensure that VOLNSNS=YES is in the DEVSUPxx member of PARMLIB. Otherwise, job failures may occur with a drive with the incorrect microcode load being allocated. In the stand-alone (non-system managed environment), IBM recommends that all the 3592 Model E05 devices under the same control unit be homogeneous for easier separation and management, even though the control unit allows a mix of 3592 Model E05 devices (encryption capable and non-encryption capable).
IBM Tape Library	As described in Introduction for encryption-capable TS1120 tape drive, z/OS DFSMS and related licensed programs provide full support for the encryption-capable TS1120 tape drive and MEDIA5, MEDIA6, MEDIA7, and MEDIA8, with z/OS V1R4 and above, with support for media types MEDIA9 and MEDIA10 being provided with z/OS V1R5 and above. The system-managed tape library support allows the tape drives to operate in an ATL or MTL environment as 3590 Model B1x devices, providing device allocation and tape media management support. As appropriate for the library type and model, this support allows the encryption-capable TS1120 tape drive to coexist with other emulated 3590-1 tape drives in the same tape library. However, prior to using the new encryption-capable TS1120 tape drive, ensure that all existing 3592 Model J1A and all existing (base support) 3592 Model E05 tape drives have their microcode upgraded to recognize and enable the EEFMT2 formatted cartridges to be relabelled/reused on the 3592 Model J1A and the base 3592 Model E05. Also, ensure that VOLNSNS=YES is in the DEVSUPxx member of PARMLIB. Otherwise, job failures may occur with a drive with the incorrect microcode load being allocated. In addition to this, in the system-managed tape library environment, all 3592 Model E05 drives under the same control unit must have the same recording format capabilities and report under the same ERDS physical identifier (EPI). So if one of the 3592 Model E05 devices has encryption enabled then all of the 3592 Model E05 devices under that same control unit must also have encryption enabled. This ensures that all of the devices under the same control unit are homogeneous and that each device under the same control unit is capable of handling the request. A tape configuration database (TCDB) with EEFMT2 volume records can coexist with lower-level systems. Coexistence support is provided at z/OS V1R4 and above to enable, during job processing, a scratch volume that was previously written with an up-level recording format to be used by a lower-level system that does not recognize the recording format. Because there is only one scratch pool per media type and that scratch pool can be used across systems at different levels of support, this support ignores the recording format that the volume was previously written in and enables the scratch volume to be used on the lower-level system (refer to coexistence APAR OA17573).
DFSMSdfp Device Services/AOM	Coexistence is provided in the Device Service Exit for z/OS V1R4 and above. This allows an encryption-capable 3592 Model E05 drive to come online as a non-encryption capable 3592 Model E05, with the EPI value stored as X'12' in the UCB class extension (UCBCXEPI field in IECUCBCX mapping macro). This allows an encryption-capable drive to be used as a non-encryption capable drive on systems that do not have the full function support installed (refer to coexistence APARs OA16116 and OA16117). When the device services full function support APAR is installed, the Device Service Exit will check if the enabling APAR is also installed. If it is, the Device Service Exit will record the EPI value in the UCB class extension as X'13'. The coexistence support will recognize the new EPI value and display the real device type as 3592-2 for DS QTAPE,MED command. The reason is the new encryption-capable 3592 Model E05 drive looks and acts exactly the same as a non-encryption capable drive in coexistence systems that do not have the full function support installed.
HSMplex	In an HSMplex, all systems in the HSMplex should have full support for the 3592-2E tape subsystem before any instance of DFSMShsm uses tape hardware encryption. If any system does not fully support tape hardware encryption in an HSMplex with tape hardware encrypted tapes, a request for tape input can fail because a 3592-2E device is not available on that system.
OAMplex	For OAM's object support customers, in addition to the planning steps required for migration to the software support for the encryption-capable TS1120 tape drive tape drives in the stand-alone and IBM tape library environments, there are coexistence considerations your installation must take into account before you install the software in an OAMplex: For the encryption-capable TS1120 tape drive support, OAM object tape coexistence support is provided at z/OS V1R4 and above, through installation of the full support PTF without the device services enabling PTF. OAM coexistence support prevents lower-level systems from selecting volumes with ERDS Physical Identifier (EPI) values for object write requests that are not supported on that system. OAM object support has coexistence considerations when running in an OAMplex environment with at least one system with the full support installed and enabled and at least one system without the full support for the new devices installed and enabled. In this mixed support environment, it is possible for a retrieve request to be received for an object that resides on a tape cartridge volume written in the EEFMT2 format by a system that does not have the encryption-capable TS1120 tape drive full support installed. Coexistence support is provided that allows OAM to attempt to locate an instance of OAM in the OAMplex where the full support is installed and enabled. If an instance of OAM is found where the request can be processed, the OAM on the system where the request originated will ship the retrieve request, if the object is not greater than 50 MB, to the target system using XCF messaging services. Once encryption-capable TS1120 tape drive devices are used in an OAMplex environment and objects are written to tape volumes with the new EPI value recorded, it is expected that any OAM on a system where the full support is installed and enabled is eligible for processing requests using that volume. Therefore, encryption-capable TS1120 tape drive devices must be available to all instances of OAM where the full support is installed.
OCE (Open / Close / End-of-Volume)	The FILEE parameter list is now longer to accommodate the possible KEK labels (key labels) and their encoding mechanism. The version of the FILEE parameter list (TEPEVER) has been updated (to a 2) to reflect the longer FILEE parameter list. Before referencing the key-label related fields in the FILEE parameter list, ensure that either the version is set to 2 or the TEPMCRYP bit is “ON”. When the TEPMCRYP bit is “ON”, the key-label related fields contain pertinent data, otherwise these fields will contain binary zeroes. Coexistence support is added at z/OS V1R4 and above to prevent an encrypted tape from being used on a lower-level system. If an encrypted volume is detected during OPEN processing on a system that does not have all of the encryption support installed, abend code 613-84: 'no software support for the media type or the recording technology' is issued (refer to coexistence APAR OA17479).
RMMplex	For the encryption-capable TS1120 tape drive support, RMM coexistence support is provided at z/OS V1R4 and above, either through installation of the full support RMM PTF without the device services enabling PTF, or by installation of the toleration APAR OA16524. This allows the coexisting system to tolerate tapes written by the encryption-capable TS1120 tape drive in EEFMT2 format and their associated key labels. If client/server is used, APAR OA16523 (preconditioning) is also required and must be installed on all client/server systems before OA16524 toleration is installed on any client/server systems. If you plan to fallback from full function system with encryption function to any other level without encryption, toleration is required on that fallback system also.