Perhaps you did not do the skip or the rewind and then skip?
Verifying
The only method to verify that a system backup will correctly restore with no
problems is to actually restore the mksysb onto another machine. This should
be done following each individual company's DISASTER RECOVERY
PLAN.
To minimize problems due to tape media damage, perform the following tests.
WARNING: These tests only verify that the tape media can be read and will not guarantee that a mksysb will be
restored successfully.
Data verification
1.Using SMIT
a.Execute the following command:
smit lsmksysb
A dialog box will appear.
DEVICE or FILE [/dev/rmt#]
Number of BLOCKS to read in a single input [ ]
(Leave blank to use a system default)
b.Type or select values and press enter only after making the desired changes.
2.Execute the following commands:
tctl -f /dev/rmt# rewind
restore -s4 -Tvqf /dev/rmt#.1 > /tmp/mksysb.log