A fix is available
APAR status
Closed as program error.
Error description
WHEN USING IMS v12, IF EXTERNAL TRACE DATASETS ARE DEFINED WITH BLKSIZE OF 4004 ( PRE IMS v9 MINIMUM BLKSIZE ) THE DATASET WILL BE MADE UNUSABLE AS FOLLOWS: . 1. DEFINE EXTERNAL TRACE DATASETS DFSTRA01 / DFSTRA02 WITH LRECL=4004 AND BLKSIZE=4008 2. ISSUE COMMAND : /TRACE SET ON TABLE DISP OPTION LOG 3. NO ERROR MESSAGE. DCB NOW SET TO LRECL=4016 + BLKSIZE=4008 LRECL IS GREATER THAN BLKSIZE, DATASET NOT USEABLE
Local fix
DEFINE EXTERNAL TRACE DATASETS WITH CORRECT LRECL AND BLKSIZE
Problem summary
**************************************************************** * USERS AFFECTED: All IMS V13 users of external * * trace. * **************************************************************** * PROBLEM DESCRIPTION: IMS does not detect external * * trace datasets with an invalid * * block size. * **************************************************************** * RECOMMENDATION: INSTALL CORRECTIVE SERVICE FOR APAR/PTF * **************************************************************** IMS does not detect external trace datasets that have an invalid block size. This can occur if a user brings up IMS with external trace datasets that were allocated before IMS 9 when the LRECL was increased from 4004 to 4016. If a customer has their external trace datasets allocated with a LRECL of 4004 and a block size of 4008 and IMS attempts to use these datasets, the LRECL is changed to 4016 but the block size remains at 4008. IMS does not detect the problem, but the datasets are unusable.
Problem conclusion
GEN: KEYWORDS: *** END IMS KEYWORDS *** The code in DFSTRA40 that checks to ensure the block is at least the LRECL+4 (4020) is comparing against a value of zero instead of 4020. IMS Module Changed ================== DFSTRA40 The minimum block size check is modified to compare against the low half of the word that contains the minimum block size instead of the high half word. GEN: KEYWORDS: *** END IMS KEYWORDS *** The code in DFSTRA40 that checks to ensure the block is at least the LRECL+4 (4020) is comparing against a value of zero instead of 4020. IMS Module Changed ================== DFSTRA40 The minimum block size check is modified to compare against the low half of the word that contains the minimum block size instead of the high half word. The following publication updates are made by this APAR: IMS Version 13: Messages and Codes, Volume 1: DFS Messages GC18-9712-00 Modify the Explanation and System Action for the DFS2868W message as follows: Explanation: One of the external trace disk data sets has a block size smaller than the other data set or the block size is smaller than the minimum size. Both external trace datasets should be the same size and specify block sizes of at least 4020. In the message text: nnnnnnnn The DD name of the external trace data set with the block size error. System Action: IMS will not use the external trace data set with the error. If both data sets have errors, message DFS2867A is issued and the user can send the trace tables to the IMS log or keep them in storage. IMS Version 13: System Definition GC19-3021-00 In chapter 13 (Setting up IMS for Diagnostics), change the LRECL and BLKSIZE descriptions for the external trace data sets. This is under the section titled "Creating output data sets with correct attributes". For DFSTRA01 and DFSTRA02 LRECL 4016 BLKSIZE The block size must be a multiple of the LRECL (4016) with an additional 4 bytes for the block descriptor work. The formula (LRECL*N)+4 can be used to compute the block size. Recommendation: Use a BLKSIZE of 20,084. This is five logical records in length (4016 bytes, multiplied by 5) plus the block descriptor word (4 bytes) For DFSTRA0T LRECL 4016 BLKSIZE The block size must be a multiple of the LRECL (4016) with an additional 4 bytes for the block descriptor work. The formula (LRECL*N)+4 can be used to compute the block size.
Temporary fix
Comments
APAR Information
APAR number
PM78533
Reported component name
IMS V13
Reported component ID
5635A0400
Reported release
300
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2012-12-05
Closed date
2012-12-25
Last modified date
2013-10-04
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UK90610
Modules/Macros
DFSTRA40
GC18971200 | GC19302100 |
Fix information
Fixed component name
IMS V13
Fixed component ID
5635A0400
Applicable component levels
R300 PSY UK90610
UP13/01/05 P F301
Fix is available
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Document Information
Modified date:
14 December 2020