SAS changes that support EAV features were first made available with SAS 9.2 maintenance releases in November 2009. Support is available for all EAV features in SAS 9.3. For earlier releases, support is available as described below. See the Glossary at the end of this SAS note for a definition of the terms used here.
Summary of EAV features provided by z/OS
General considerations for SAS support
Note: At this time EAV is not supported for the load module libraries that are used in a CLIST or REXX exec for interactive SAS sessions. A fix is under consideration for a future release.
SAS Release | z/OS V1R10 and Initial V1R11 | z/OS V1R12 (and V1R11 Systems with Additional EAV Maintenance) |
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Prior to 9.2M2 | Capabilities:
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Limitations (related to features that were new in z/OS V1R12):
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9.2M2 and 9.2M3 | Capabilities:
Same as prior releases but with the following additions:
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Capabilities:
In addition to the support that was available with z/OS V1R11, SAS 9.2M2 and SAS 9.2M3 can process the additional non-VSAM data sets that can reside in EAS. Limitations (related to features that were new in z/OS V1R12):
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SAS 9.3 | Capabilities:
Same as prior SAS releases with the addition of support for the EATTR option on the FILENAME and LIBNAME statements.
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Capabilities:
Limitations present in SAS 9.2M2 and SAS 9.2M3 have been removed:
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Term | Definition |
---|---|
EAS | Acronym for extended addressing space. The EAS is the set of locations on an EAV for which the cylinder address is >= 65,536 (0x10000). |
EAS-eligible data sets | This term applies to the types of data sets that are eligible to reside in the extended addressing space (EAS) of an extended address volume (EAV). Which types of data sets are eligible depends on the release of z/OS. |
EAV | Acronym for extended address volume. An EAV is a volume with more than 65,520 (0xFFF0) cylinders. Before the introduction of EAV support in z/OS V1R10, all direct access storage device (DASD) volumes supported on z/OS used a 16-bit value to address cylinders on the device. EAVs use a 16-bit address for cylinders 1-65520 and a 28-bit cylinder address for cylinders in the EAS (defined below). |
extended attributes | This refers to a data set created with format 8/9 DSCBs in the VTOC. These new format DSCBs provide room for additional information about a data set and use 28-bit cylinder addresses to enable support for data sets having DASD extents in EAS. Important: A data set can have extended attributes without residing in EAS. In order for a data set to have extended attributes, it must be EAS-eligible and must be created with EATTR=OPT on an EAV. |
extended-format sequential data set | A sequential, non-VSAM data set that was allocated with DSNTYPE=EXTREQ or DSNTYPE=EXTPREF specified in the JCL (or equivalent options in an SMS data class). Extended-format sequential data sets are processed like ordinary sequential data sets, but the system controls the low-level format of the data set and provides additional capabilities such as striping, compression, an unlimited number of tracks per volume, etc.
Note: This concept is completely separate and distinct from “extended attributes” (see entry in glossary). Extended-format sequential data sets may or may not have extended attributes. In addition, other types of data sets also may or may not have extended attributes. |
track-allocated space | Space in EAS is always allocated in multicylinder units. Track-allocated space refers to the range of cylinder addresses that can be represented in 16 bits; that is, 65,535 or lower. This range of addresses below the EAS exists to provide compatibility with older programs that do not support data sets that have extended attributes. (See definition below.) In some documentation, this is called “base Addressing space." |
VTOC | volume table of contents |
To summarize:
Product Family | Product | System | SAS Release | |
Reported | Fixed* | |||
SAS System | Base SAS | z/OS | 8.2 TS2M0 |
Type: | Usage Note |
Priority: |
Date Modified: | 2012-06-06 09:36:31 |
Date Created: | 2009-05-08 11:09:53 |