ITEM: D5439L

Mksysb fails with error 0512-005 without asking for second volume.

Question:

I was doing a mksysb of my system. The backup seemed to run for two and a
half hours and then failed with

        0512-005 tape write error: unexpected EOF

It seems like mksysb is failing to recognise the end of the tape.

Response:

There is currenlty a fix out for this behavios. As a workaround, the
below script should allow the mksysb command to correctly bridge to
a second or third tape.

   NOTE:  This modification is ONLY for a SINGLE tape/tape-drive
   combination.  Determine what tape and tape drive you will be using
   for the backup before performing this workaround.

   NOTE:  When running mksysb after this procedure, be sure to use the
   correct density setting to match the rmtX special device.

   1.  Make a backup copy of /usr/bin/mksysb.

   2.  Use the following table to determine which "-S SIZEb" flag needs to
       be added to the tar command at the end of /usr/bin/mksysb.  "SIZE"
       is the size in 512-byte blocks to be expected from the tape.

       NOTE:  After the number for the -S flag, you must put in the "b"
       flag to denote these are blocks, e.g. "-S 11110b".

       NOTE:  The block-size setting for a 1/4-inch tape drive should be
       512 and for an 8mm or 4mm dat tape drive should be 1024.  However,
       if you are using a 7208 8mm tape drive and you do not have PTF
       U403173 on your system, you must use a block size of 512 and a
       SIZE flag of "-S 11110b" (half the value shown in the table).
       The capacity in this case will be 1.15GB.

      ----------------------------------------------------------------
         Tape Drive               Flag             Capacity
       ------------------      ------------       -----------
       7206 4mm dat            -S 222200         2.3 Gbytes

       7208 8mm                -S 222200         2.3 Gbytes

       7207-001 1/4 inch
            6150 tape          -S 14700          150 Mbytes
            6250 tape          -S 24700          250 Mbytes

       7207-011 1/4 inch
            6150 tape          -S 14700          150 Mbytes
            6250 tape          -S 24700          250 Mbytes
            6525 tape          -S 51000          525 Mbytes

       7207-012 1/4 inch
            6150 tape          -S 14700          150 Mbytes
            6250 tape          -S 24700          250 Mbyte
            6525 tape          -S 104700         1.2 Gbytes
       ----------------------------------------------------------------

   3.  Add the proper "-S SIZEb" flag to the /usr/bin/mksysb file.

       The original line looks like this:

          tar -cvdpf"$DEVICE" -L"$archive_lst"

       The corrected line should look like this (where SIZE is chosen from
       the table in step 2):

          tar -cvdpf"$DEVICE" -S SIZEb  -L"$archive_lst"

       EXAMPLE:  For a 7208 8mm tape drive:

          tar -cvdpf"$DEVICE" -S 222200b -L"$archive_lst"

  NOTE:  The Info Explorer and man pages entries for the tar command
  are incorrect.  They state that the "b" suffix specifies the number of
  512-byte blocks per volume (first format).  In reality, the "b" suffix
  specifies the number of records of a size determined by the "-b" flag.
  The default for the "-b" flag (if not specified) is 20.  Therefore,
  each unit for the -Ssizeb flag is really 20 multiplied by 512, or
  10240, bytes.  The values shown in the preceding table are correct for
  the various tape/tape drive configurations.  A documentation APAR has
  been created to correct the documentation.



Support Line: Mksysb fails with error 0512-005 without asking for second volume. ITEM: D5439L

Dated: August 1993 Category: N/A

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