OA58651: BPXWMIGF ZFS ZFS2ZFS Z2Z DATA CORRUPTION INTEGRITY FILES SMALL FRAGMENTED

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• When using BPXWMIGF to migrate a zFS file system to another zFS
  file system on z/OS 2.4, any files with a size of
  52 bytes or less are not copied properly from the source to the
  destination.
  
  In the test cases ran, the files that were 52 bytes or less in
  size on the source file system ended up with zeros
  in the destination file system.
  
  Note that this issue only applies to using BPXWMIGF for zFS to
  zFS migration on z/OS 2.4. This issue does not impact any
  users using BPXFMIGF to migrate HFS to zFS.
  
  KNOWN IMPACT:
  After using the BPXWMIGF tool to migrate a source zFS file
  system to a destination zFS file system, any files with
  52 bytes or less will contain zeros starting at offset zero into
  the file.
  
  In addition, any FRAGMENTED files will have the same type of
  corruption. Fragmented files were used in legacy zFS
  file systems created prior to z/OS R13.
  
  The files in the source file system are not affected.
  

Local fix

• BYPASS/CIRCUMVENTION:
  Do not use the BPXWMIGF tool to migrate zFS to zFS file systems
  until the ++APAR/PTF for this APAR has been applied.
  
  RECOVERY ACTION:
  Customers that have already used BPXWMIGF to migrate a zFS file
  system to another zFS file system have to validate
  the destination file system.
  
  Any files in the source file system that are 52 bytes or less
  have the potential to be corrupted in the
  destination file system.
  
  The following shell command can be used to determine if the file
  in the source file system is 52 bytes or less:
  
       find /path/to/the/root -xdev -size -53c
  
  In addition, this issue impacts any migration involving a source
  file system that has a legacy FRAGMENTED file format. In this
  case, any FRAGMENTED file irrespective of the size has the
  potential to be corrupted.
  
  Use the following shell command to determine if a file is
  FRAGMENTED:
  
       zfsadm fileinfo -path <filename>
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * zFS Version 2 Release 4                                      *
  * zFS FMID:HZFS440                                             *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * BPXWMIGF migration of inline or                              *
  * fragmented files in a ZFS source file                        *
  * system may result in the files                               *
  * containing binary zeroes in the target                       *
  * ZFS file system.                                             *
  *                                                              *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * APPLY PTF                                                    *
  ****************************************************************
  When using the bpxwmigf command to migrate a source zFS file
  system to a target zFS file system, the contents of inline files
  
  (less than 53 bytes) or fragmented files may contain binary
  zeros. The problem occurred when the read of the source file
  specified the incorrect offset to write the file in the target
  file system. Bytes with binary zeros were written ahead of
  the bad offset.
  

Problem conclusion

• Code has been added to set the offset to zero when the file
  being read is either inline or a fragmented file.
  

Temporary fix

• *********
  * HIPER *
  *********
  

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UJ01669

Modules/Macros

• IOEFSKN  IOEFSUTL IOEZADM  IOEDUMPF IOEFSCM  IOEFSTHD IOEAGFMT
  IOEAGSLV
  

Fix information

• Fixed component name

  ZFS ZSERIES FIL

• Fixed component ID

  5696EFS00

Applicable component levels

• R440 PSY UJ01669

     UP19/12/21 P F912 ¢

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.