zEDC Compression
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zEDC Compression

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Article ID: 42516

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Updated On: 03-03-2025

Products

Allocate DASD Space and Placement Disk Backup and Restore - MVS DISK BACKUP AND RESTORE- ADD-ON OPTIO DISK BACKUP AND RESTORE

Issue/Introduction



What is zEDC Compression and how does it affect CA Disk, CA Allocate and CA Vantage ?

Environment

Release: 
Component:

Resolution

zEDC is a hardware compression so it is the z14/z13/EC12/BC12 architecture which performs
compression and decompression of data at a hardware level in a transparent way to the
tasks which are asking to access the data.
 
Regarding CA Vantage SRM r14.0:
 - Z14 Compatibility  with no other PTFs needed.
 
Regarding CA Disk r12.5:
  - zEDC compressed user data sets are a supported format for Backup/Archive/Restore, Move/Copy, etc.
  - zEDC compression is not supported as a compression technique. It is not a good fit due to the
    amount of data needed in a unit (4 KB) and some of our records are considerably smaller.
  - Allocating a data set as zEDC compression requires it to be a PSE which is not allowed for a CA Disk Archvol.
 
Regarding CA Allocate r12.5:
CA Allocate does not interfere with zEDC compression. zEDC compression is performed
by the operating system completely outside of CA Allocate processing.
 
The only limitation is that CA Allocate users will not have the ability to modify the
ZR and ZP SMS Dataclass Attributes via the ASR routines,
(the way they have the ability to modify other SMS attributes using the ASR routines).

CA Allocate is involved with the allocation of data sets. The only interaction CA Allocate would have with the Z/EDC function is with the use of the DF/SMS DATACLAS. CA Allocate has the ability to change a DATACLAS name and modify a subset of DATACLAS attributes. For the Z/EDC functionality, IBM has added the DATACLAS attributes "ZR" and "ZP". CA Allocate does not have the ability to modify these attributes. For all other functions that CA Allocate is performing at your installation there isn't any known problem. 

Allocate is not able to modify specific attributes of a SMS DATACLASS.  Allocate can add or remove a DATACLASS from an allocation. Example ASR code would look like this:

 

IF &VAMENVIR = ‘ACS’ THEN

DO

 IF &DSN = ‘MY.TEST.DSN.WANT.COMPRESSION’ THEN

 DO

  SET &DATACLAS = ‘COMPRESS’  /* SET A DATACLASS */

 END

 ELSE

 DO

  SET &DATACLAS = ‘’   /* REMOVE THE DATACLASS */

 END

END

 

The Allocate User’s Guide documents which variables are available in the ACS environment. These variables provide the ability to screen which data sets you want to add the DATACLAS which supports compression.