A fix is available
APAR status
Closed as new function.
Error description
Increase the block size supported for native CMS tape I/O from 64KB to approximately 1MB.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: Users of products or applicatons that * * exploit native CMS tape I/O functions * * (RDTAPE and WRTAPE) * **************************************************************** * PROBLEM DESCRIPTION: * **************************************************************** * RECOMMENDATION: APPLY PTF * **************************************************************** The native CMS tape support block size limit is increased from 64K to roughly 1M. This enables applications and products such as backup solutions that exploit the native interfaces to use larger blocks, which can improve their performance.
Problem conclusion
Temporary fix
FOR RELEASE ES-CMS-730-BASE : PREREQ: NONE CO-REQ: NONE IF-REQ: NONE
Comments
Tape channel programs are now constructed using multiple data-chained CCWs to accommodate a larger block size. The maximum tape blocksize supported is available in a new field in NUCON, MAXTAPBS. In CMS releases without this support, this field is zero, indicating that the maximum block size is 65,535. The RDTAPE macro no longer limits a numeric buffer length to 65,535 bytes. The associated MNOTE is no longer produced and the buffer length is not changed. The length is still checked at run time and will produce return code 1 if it exceeds the supported maximum.
APAR Information
APAR number
VM66724
Reported component name
VM CMS
Reported component ID
568411201
Reported release
730
Status
CLOSED UR1
PE
NoPE
HIPER
NoHIPER
Special Attention
YesSpecatt / New Function / Xsystem
Submitted date
2023-10-09
Closed date
2023-11-10
Last modified date
2024-04-04
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UM90377
Modules/Macros
DMSNUC DMSTIO DMSTLB DMSTLW DMSZNUC NUCON NUCONP NUCONPZ NUCONZ RDTAPE WRTAPE
SC24626273 |
Fix information
Fixed component name
VM CMS
Fixed component ID
568411201
Applicable component levels
R730 PSY UM90377
UP23/11/14 P 2401
Fix is available
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Document Information
Modified date:
04 April 2024