IBM Support

Compression with ZLIB algorithm - Save Commands and APIs

News


Abstract

IBM i 7.5 and IBM i 7.4 add another option to Save commands and APIs for Save Files and Optical (including Virtual Optical) that have the data compression parameter. The new ZLIB option produces a smaller result and improves performance over existing options.

Content

You are in: IBM i Technology Updates > General IBM i Operating System > Compression with ZLIB algorithm - Save Commands and APIs

The ZLIB algorithm provides another option for data compression. Test results show it is often faster than previously available algorithms and generally produces a smaller result, though actual results vary, depending on the compressibility of the data. The new algorithm automatically uses the on-chip Nest Accelerator (NX) GZIP when it runs in Power10 compatibility mode on a Power10 processor and is therefore faster and less CPU-intensive than previously available compression options.

For Save, the previously available options for compression were *LOW, *MEDIUM, and *HIGH.  The additional option for IBM i 7.5 and IBM i 7.4 TR 7 is *ZLIB.

There is no change in the Restore processing.  The Restore process automatically determines the compression that was used.

Here is a list of the Save commands that support *ZLIB:

  • SAV
  • SAVCFG
  • SAVCHGOBJ
  • SAVDLO
  • SAVLIB
  • SAVLICPGM
  • SAVOBJ
  • SAVSECDTA
  • SAVSYS
  • SAVSYSINF
Here is a list of the APIs that support *ZLIB:
  • Save Object List (QSRSAVO)
  • Save Object (QsrSave)
  • Save to Application (QaneSava)
IBM i 7.5 note:  For the System Administrator to perform a save operation with DTACPR(*ZLIB) and specify TGTRLS(*PRV) -or- TGTRLS(V7R4M0), it is necessary to load the IBM i 7.5 PTFs listed at the end of this topic.  Without the IBM i 7.5 PTFs applied, the operation would fail with this message:
  • CPF37A9 - Specified data compression not supported for target release.
For more information about this topic, see the following sections in IBM Documentation:
For more information about performance aspects, see the topic "What are some considerations for use of data compression in IBM i?" in the document IBM i on Power - Performance FAQ.
Required PTFs for this support:
IBM i 7.5:
   - PTF MF70497
   - PTF SI81754
IBM i 7.4:
   - PTF MF70498
   - PTF SI81755
   - PTF SI81756

[{"Type":"MASTER","Line of Business":{"code":"LOB57","label":"Power"},"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SWG60","label":"IBM i"},"ARM Category":[{"code":"a8m0z000000cwp6AAA","label":"Save Restore"}],"ARM Case Number":"","Platform":[{"code":"PF012","label":"IBM i"}],"Version":"7.4.0;7.5.0"}]

Document Information

Modified date:
10 March 2023

UID

ibm16579393

Page Feedback