INTERMITTENT ORA-01115 ORA-27091 ORA-27069 WHILE RUNNING BACKUPS (Doc ID 1296217.1)

Last updated on JUNE 06, 2015

Applies to:

Oracle Database - Enterprise Edition - Version 10.2.0.4 and later
Information in this document applies to any platform.
10.2.0.1 thru 10.2.0.5
Potentially 11.1
Fixed in 11.2


Symptoms

Any of the following errors are seen in the alert.log and/or trace files

Generic example from alert log:

Errors in file <trace file name>:

  • ORA-19883: Unused Block Optimization stopped for datafile <data file name> 
  • ORA-01115: IO error reading block from file <data file name> (block # <Block#>)
  • ORA-27091: unable to queue I/O
  • ORA-27069: attempt to do I/O beyond the range of the file
  • Additional information: <Block#>
  • Additional information: 1
  • Additional information: <Incorrect last Block#>

Also the trace file may show:

  • "Error: Bitmap <bitmap#> for file <file#> at block <block#> of datafile <file#>
     has incorrect block type, expected: 30, got:<different block type like 6>"

The errors can occur within any of several datafiles and tablespaces during the backups

e.g.
...
ORA-01115: IO error reading block from file +MT_DATA_01/MT/datafile/abd.451.677765651 (block # 2899969)
ORA-17510: Attempt to do i/o beyond file size



Another symptom is evidence of TAIL BITMAP block optimization after the backup

*** ACTION NAME:(0000145 STARTED16) 2010-12-30 23:09:54.192
*** MODULE NAME:(backup full datafile) 2010-12-30 23:09:54.192
*** SERVICE NAME:(abc_backup) 2010-12-30 23:09:54.192
...
...
    Bitmap 2 for file xx at block xxxx of datafile ...
    Rereading bitmap...
    Backup Optimization context dump (krbodmpcx)



You can find several key indicators in the Trace file
Bold indicates key identifiers or characteristics of the problem


*** 2010-12-30 23:09:54.192
*** ACTION NAME:(0000145 STARTED16) 2010-12-30 23:09:54.192
*** MODULE NAME:(backup full datafile) 2010-12-30 23:09:54.192
*** SERVICE NAME:(abc_backup) 2010-12-30 23:09:54.192
*** SESSION ID:(939.28844) 2010-12-30 23:09:54.192
Bitmap 2 for file 179 at block 2891777 of datafile 179 has incorrect block type, expected: 30, got:6
Rereading bitmap 2 for file 179 relocated  at block 2899969 in datafile 179
Backup Optimization context dump (krbodmpcx)

============================================
Information about file being optimized
Datafile name : +ABC_DATA_01/ABC/datafile/X2_idx_h1.451.677765651
Absolute file number : 179
Relative file number : 179
Tablespace number : 176
Tablespace blocksize : 16384
Tablespace is SFT : FALSE
Chkpoint SCN of datafile: 193955971853
Last block in backup : 2891776            <
Information about datafile holding bitmaps
Absolute file number : 179
Relative file number : 179
Chkpoint SCN bitmap file: 193955971853
Blocks mapped per bit : 4
Blocks mapped per byte : 32
Blocks mapped per bitmap: 516096
Bitmaps related information
Number of bitmaps used : 6
Number of head bitmaps : 2
Number of tail bitmaps : 4                     <
Number of bitmaps read : 2
Space header related information
SCN of Space Header : 193956083782
Last deallocation scn : 170474335925
Last block in file : 2899972
Space header rel-fno(hc): 179
Size of file in blocks : 2899972
End of data blocks : 2899968          <969  reporting the ORA-1115 and ORA-17510
Max size of file : 3276804
Information about current bitmap
SCN bitmap : 172874328713
Current bitmap number : 2
Valid bitmap? : NO
First block in bitmap : 516101
Last block in bitmap : 1032196         
First block in bytemap : 1032165
Statistics fields
Number of blocks read : 1030943
Number of unread blocks : 64
Status fields
All bitmaps processed? : NO
============================================

ORA-19883: Message 19883 not found; product=RDBMS; facility=ORA
; arguments: [+ABC_DATA_01.../X2_idx_h1.451.677765651]
ORA-01115: IO error reading block from file +ABC_DATA_01.../X2_idx_h1.451.677765651 (block # 2899969)
ORA-17510: Attempt to do i/o beyond file size

Cause

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