This section provides information on device and system file topics.

• Adabas File Characteristics

• DFSMS-Managed Files

• Large Format File Support

• Supported Adabas Device Types

• Adding or Updating Devices

• Enhanced Backup and Restore Performance in Tape Sequential Files

---

Adabas File Characteristics

Adabas container data sets (ASSO, DATA, WORK, TEMP, SORT, PLOG, CLOG, RLOG, ALOG, or DSIM) consist of fixed-length records (RECFM=F), with a data set organization which is compatible with sequential data sets (DSORG=PS).

Both basic format and large format data sets are supported for Adabas containers.

Extended format data sets (also known as striped data sets) are not supported for Adabas containers. If an attempt is made to open an Adabas container using an extended format data set, an error message will be issued and the job will be terminated.

DFSMS-Managed Files

Adabas files can be managed by DFSMS, and placed on disk devices belonging to a DFSMS Storage Group. This allows Adabas to take advantage of the storage management features of DFSMS, for example allowing DFSMS to administer the space requirements of data sets when they are allocated or extended.

The procedure for extending Adabas files differs according to whether the file is DFSMS-managed or not. See DBA Tasks > Database Space Management > Increasing Associator and Data Storage Space for more details. See also the descriptions of ADABAS INCREASE and ADADBS ONLINCREASE in the Utilities manual.

If Adabas container files are encrypted using the add-on Adabas Encryption product (product code AEZ), DFSMS management is mandatory. Otherwise, it is optional.

Large Format File Support

Adabas supports large format files, a feature introduced with IBM z/OS 1.7.

Prior to large format file support, the extents of an Adabas container (ASSO, DATA, WORK, TEMP, SORT, PLOG, CLOG, RLOG, ALOG, or DSIM data sets) were only able to occupy 65,535 tracks per volume. With large format file support, the data set extents can now occupy an entire volume.

As before, each data set can have up to 16 extents on a volume and can span up to 59 volumes. For ASSO and DATA, up to 99 separate data sets are supported.

In addition to supporting large format files for container data sets, Adabas sequential data sets (typically those read or written by the Adabas utilities) can also take advantage of IBM large format file features.

When allocating a new Adabas data set (container or sequential) where the space on any single volume can exceed 65,535 tracks, the DSNTYPE=LARGE parameter needs to be specified in the JCL. If the data set is eligible to use the cylinder-managed space on an EAV disk device, EATTR=OPT needs to be specified in the JCL, in addition to DSNTYPE=LARGE. Once a large format file is allocated, the DSNTYPE=LARGE and EATTR=OPT paramaters are no longer necessary in JCL for the file.

For further information about the DSNTYPE JCL parameter, as well as for details about the IBM PARMLIB parameter BLOCKTOKENSIZE(REQUIRE) in member IGDSMSxx, refer to the IBM z/OS documentation provided in section Processing Large Format Data Sets in the DFSMS: Using Data Sets guide.

Supported Adabas Device Types

The standard characteristics of the device types supported via the ADARUN DEVICE parameter in z/OS environments are summarized in the following table. Adabas block sizes and blocks per track are provided for each Adabas component for each device type.

Device	Trks/Cyl	ASSO	DATA	WORK	PLOG/RLOG	CLOG/ALOG	TEMP/SORT/DSIM	Notes
3390	15	2544:18	5064:10	5724:9	5724:9	5064:10	8904:6	1
8390	15	3440:14	6518:8	10706:5	10706:5	8904:6	8904:6	1
8391	15	4136:12	10796:5	13682:4	13682:4	8904:6	18452:3	1
8392	15	4092:12	12796:4	18452:3	18452:3	18452:3	18452:3	1
8393	15	4092:12	27644:2	27990:2	27990:2	27990:2	27990:2	1
3380	15	2004:19	4820:9	5492:8	5492:8	4820:9	7476:6	2
8380	15	3476:12	6356:7	9076:5	9076:5	9076:5	9076:5	2
8381	15	3476:12	9076:5	11476:4	11476:4	9076:5	9076:5	2
8385	15	4092:10	23292:2	23468:2	23468:2	23468:2	23468:2	2

Notes:

1. The 3390 and 839n device types are to be used for all disks emulating 3390 devices. Device types 839n provide larger block sizes than the default 3390.
2. The 3380 and 838n device types continue to be supported for 3380 devices. Device types 838n provide larger block sizes than 3380.

Adding or Updating Devices

Any users requiring to add a new Adabas device type, or else update an existing Adabas device type, should contact their Software AG support representative for assistance.

Enhanced Backup and Restore Performance in Tape Sequential Files

Adabas exploits IBM’s large block (more than 32,760 bytes) support for sequential access methods BSAM and QSAM under z/OS version 2 release 10 and above. ADAIOR supports tape drives with a block size of up to 256K for 3590 devices and 64K for 3490/3490E devices.

This support can provide performance benefits for any utility writing to tape (for example, ADASAV).