ABSTRACT: Incompatible <Block> <Sizes> for AIX 3.1

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       | NOTE:  The information in this document has NOT been     |
       | verified for AIX 4.1.                                    |
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  ABOUT THIS DOCUMENT

       This document contains steps to the resolution to the
       problem and cause of backup <tape> <block> <size> and is appli-
       cable to AIX 3.1.

  PROBLEM:

       Backup <tape> was made with <block> <size> set to 512.  When the
       user tried to restore the <tape> from the install diskettes,
       the <block> <size> was set to 1024.  The machine gave a read
       error when it tried to read the <tape>.

  CAUSE:

       These <block> <sizes> are inconsistent because the information
       is taken from two different places.  When the <tape> is made
       up, the <block> <size> is taken from the ODM (CuAt specif-
       ically).  When the <tape> is restored, the <block> <size> is taken
       from the install diskette.

  RESOLUTION (FOR AIX 3.1 ONLY):

       To solve the problem, change the <block> <size> that the install
       diskette uses.  To do this, use the following procedure:

       1.  Enter:

           "mkdir /tmp/inst"

           to create a temporary directory.

       2.  Enter:

           "cp /etc/objrepos/boot/mediadd.bff /etc/objrepos/boot/mediadd.bffold

           to create a backup of mediadd.bff.

       3.  Enter:

           "cp /etc/objrepos/boot/mediadd.bff /tmp/inst"

           This puts the file in the temporary directory so we can
           play with it.

       4.  Enter:

           "cd /tmp/inst"

       5.  Enter:

           "restore -xvqf mediadd.bff"

           The files which are restored are basically the ODM which
           is used by the install process.

      6.  Enter:

          "vi scsidev.add"

           Search on "block_size".  The cursor should be on "attri-
           bute = block_size".  The line above the cursor should
           read "uniquetype = tape/scsi/8mm" and the line below
           "deflt = 1024".

           Cursor down one line to "deflt = 1024" and change the
           1024 to 512.  Save the file.

       7.  Enter:

           "rm mediadd.bff"

           so that the file isn't backed up by the next command.

       8.  Enter:

           "ls | backup -ivqf mediadd.bff"

           to put the files back into the backup file.

       9.  Enter:

           "cp mediadd.bff /etc/objrepos/boot"

       10. Enter:

           "/usr/lpp/bosinst/diskette/mkinstdskt /usr/bin/bosinst.image"

           to make the install image.

       11. Enter:

           "dd if=/usr/bin/bosinst.image of=/dev/rdf0"

           to put the install image on diskette.
      12. Boot up using this new diskette as the installation
           disk.


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       the customer and depends on the customer's ability to eval-
       uate and integrate this information into the customer's
       operational environment.