A fix is available
APAR status
Closed as program error.
Error description
A PDF OSAM data set for partition 2 had filled to 4.7GB of its 8GB size when message DFS0842I OSAM DATA SET CANNOT BE EXTENDED, REASON=5 was issued. An attempted UNLOAD of the data set by a PDF utility failed with message NSX1690W OSAM DBD DBCOISLM in DD COISLM02 extents of 61 exceeded OSAM maximum allowable of 59, database unusable by IMS Diagnostics. A listing of the data set information showed: General Data Current Allocation Management class . . : IMSMAN Allocated cylinders : 7,800 Storage class . . . : IMS Allocated extents . : 61 Volume serial . . . : IMS524 + Device type . . . . : 3390 Data class . . . . . : DBOSAM Organization . . . : PS Current Utilization Record format . . . : FBS Used cylinders . . : 7,401 Record length . . . : 2048 Used extents . . . : 57 Block size . . . . : 2048 1st extent cylinders: 400 Secondary cylinders : 200 Other messages received were: DFS0844I DFSGGSP0 DBCOISLM DATASET FULL, DDNAME=COISLM02 DFS0845I DBCOISLM DATASET LIMIT REACHED, DDNAME=COISLM02 This was a multivolume OSAM data set that was contained on 11 volumes with the following allocated extents: VOLUME EXTENTS BLOCKS CYLS ACCUM ------ ---------------- ------- ---- ----- 1 8 (1 pri,7 sec) 567,000 1800 1800 2 2 (sec) 126,000 400 2200 3 6 (sec) 126,000 400 2600 4 11 (sec) 315,000 1000 3600 5 2 (sec) 126,000 400 4000 6 11 (sec) 378,000 1200 5200 7 11 (sec) 504,000 1600 6800 8 3 (sec) 63,000 200 7000 9 1 (sec) 63,000 200 7200 10 5 (sec) 126,000 400 7600 11 1 (sec) 63,000 200 7800 --------------------------------------------------------- TOTALS 61 extents 2,457,000 blocks 7800 cyls DFS730I UNABLE TO OPEN DATASET WITH DDNAME xxxxxxxx FOR REASON A,10,0F can also be issued for this error when the maximum number of OSAM extents are exceeded.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All IMS V12 full function OSAM * * (Overflow Sequential Access Method) * * users. * **************************************************************** * PROBLEM DESCRIPTION: DFS0842I OSAM DATASET CANNOT BE * * EXTENDED, REASON=5,24, DDNAME=xxxxxxxx * * message encountered while running * * applications using OSAM databases. * **************************************************************** * RECOMMENDATION: INSTALL CORRECTIVE SERVICE FOR APAR/PTF * **************************************************************** MSGDFS0842I was issued while inserting to an OSAM database resided on multiple volumes. The application was performing lots of inserts to a database. The database data set was allocated across fifty seven extents. After more inserts, an "end of volume" (EOV) request was issued for more space. This request was satisfied using four fragments, increasing the total number of extents to sixty one. This is one more than the sixty allowed under OSAM, and led to the error message. The reason that EOV exceeded the OSAM extent limit is that if EOV cannot satisfy a request with one contiguous extent, EOV will try to satisfy the request with up to five smaller extents. In the error case, EOV returned four extents under one request. OSAM needs to be modified to better handle EOV requests when a database is within five extents of it's maximum allocation. Other messages received were: DFS0844I DFSGGSP0 DBCOISLM DATASET FULL, DDNAME=xxxxxxxx DFS0845I DBCOISLM DATASET LIMIT REACHED, DDNAME=xxxxxxxx.
Problem conclusion
GEN: KEYWORDS: *** END IMS KEYWORDS *** The following parts have been modified to address the problem: DFSAOSF0 This module processes the EOV function. After the extension request is successful, it checks the total number of extents allocated so far, and if the number is 55 or more flag DCBEXT55 is set with subcode 10 in DCBWRK0+3 and passes the information back to the caller, DFSDBH10, to issue a warning message about the extents nearing the maximum allowed so the users can perform some actions to avoid the error. DFSDBH10 After macro DFSOSAM FUNC=EOV with good return code, if flag DCBEXT55 is set call DFSDBH40 to issue DFS0842I message. DFSDBH40 Issue DFS0842I message. IDCBOSD Add flag DCBEXT55 under DCBFLG1. Add field DCBWRK0 using the reserved storage. Doc change: GC18971206 Messages and Codes Replace the following message text: DFS0842I OSAM DATASET CANNOT BE EXTENDED, REASON=X, Z,dbdname ddname, dsname With the following: DFS0842I OSAM DATASET CANNOT BE EXTENDED, REASON=X, Z,dbdname ddname, dsname or OSAM DATA SET NEAR MAX EXTENTS (NN OF 60), RSN=X, Z, dbdname ddname, dsname Replace the following part: Explanation OSAM was unable to extend the named data set. A two line message, each numbered DFS0842I is issued. The first line indicates why the data set is not extendable and also contains the dbdname. The second line contains the ddname and the dsname. With the following: Explanation OSAM was unable to extend the named data set or the total number of extents allocated for the data set are 55 or more nearing the maximum allowance of 60. A two line message, each numbered DFS0842I is issued. The first line indicates why the data set is not extendable or the total extents allocated so far. It also contains the dbdname. The second line contains the ddname and the dsname. Replace the following part: 5 LCREAT30 An attempt to get another extent for the data set using the OSAM end-of-volume routine failed. The data set could not be enlarged and another extension could not be allocated. With the following: 5 LCREAT30 An attempt to get another extent for the data set using the OSAM end-of-volume routine and results in one of the following two conditions: 1. The end-of-volume routine failed. The data set could not be enlarged and another extension could not be allocated. 2. The end-of-volume routine was successful, but the total number of extents used are 55 or more nearing the allowable maximum of 60. Add the following bullet between the existing second and the third bullet under: Programmer response Take the following actions: . If the total number of extents for a data set are nearing 60 add additional space or reduce the number of DASD extents, by reorganizing the database. Replace the following part: Z subcode (hex) Meaning 01 Data control block (DCB) marked unusable. 02 DCB is DD dummy data set. It is detected by DFSAOSF0. 03 DCB is not open. It is detected by DFSAOSF0. 04 Data extension block (DEB) has reached maximum size. 05 Data set not extendable, or secondary allocation is not permitted. 06 Insufficient volumes. 07 An error occurred while locating the current volumes extents. The OSPLIT subroutine is 4 in register 15. 08 An error occurred while converting an OSAM data extension block (DEB) to an MVS DEB. The return code from the OSDEB subroutine is 4 in register 15. 09 An error occurred while constructing an OSAM DEB. The return code from the OSAMDEB subroutine is 4 in register 15. 0A DEB/DCB validation check failed. 0B This call is not for an EOV call request. 0C An error occurred while locating the current volumes extensions. The return code from the OSPLIT subroutine is 8 in register 15. 0D An error occurred while converting an OSAM data extension block (DEB) to an MVS DEB. The return code from the OSDEB subroutine is 8 in register 15. 0E An error occurred while constructing an OSAM DEB. The return code from the OSAMDEB subroutine is 8 in register 15. 0F Error releasing a captured unit control block (UCB). With the following: Z subcode (hex) - set by module DFSAOSF0: Meaning 01 Data control block (DCB) marked unusable. 02 DCB is DD dummy data set. 03 DCB is not open. 04 Data extension block (DEB) has reached maximum size. 05 Data set not extendable, or secondary allocation is not permitted. 06 Insufficient volumes. 07 An error occurred while locating the current volumes extents. The OSPLIT subroutine is 4 in register 15. 08 An error occurred while converting an OSAM data extension block (DEB) to an MVS DEB. The return code from the OSDEB subroutine is 4 in register 15. 09 An error occurred while constructing an OSAM DEB. The return code from the OSAMDEB subroutine is 4 in register 15. 0A DEB/DCB validation check failed. 0B This call is not for an EOV call request. 0C An error occurred while locating the current volumes extensions. The return code from the OSPLIT subroutine is 8 in register 15. 0D An error occurred while converting an OSAM data extension block (DEB) to an MVS DEB. The return code from the OSDEB subroutine is 8 in register 15. 0E An error occurred while constructing an OSAM DEB. The return code from the OSAMDEB subroutine is 8 in register 15. 0F Error releasing a captured unit control block (UCB). 10 The total number of extents allocated is 55 or more nearing the maximum allowance of 60 after a successful EOV function. Replace the following part: 20 End-of-volume (EOV) is already pending. 21 I/O error was encountered 22 DCB was DD dummy data set. It was detected by DFSAOS10. 23 DCB was not open. It was detected by DFSAOS10. 24 Error acquiring new extent. With the following: Z subcode (hex) - set by module DFSAOS10: Meaning 20 End-of-volume (EOV) is already pending. 21 I/O error was encountered 22 DCB was DD dummy data set. It was detected by DFSAOS10. 23 DCB was not open. It was detected by DFSAOS10. 24 Error acquiring new extent.
Temporary fix
Comments
APAR Information
APAR number
PM92590
Reported component name
IMS V12
Reported component ID
5635A0300
Reported release
200
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2013-07-09
Closed date
2013-08-27
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:
UK97062
Modules/Macros
DFSAOSF0 DFSDBH10 DFSDBH40 IDCBOSD
| GC18971206 |
Fix information
Fixed component name
IMS V12
Fixed component ID
5635A0300
Applicable component levels
R200 PSY UK97062
UP13/09/05 P F309
Fix is available
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Document Information
Modified date:
14 December 2020