Explanation

The Common VTOC access facility (CVAF) detected a VTOC index error on the volume.
dev
Specifies the device number.
volser
Specifies the volume serial number of the volume.
code
Specifies a number that represents the kind of VTOC index error encountered.
rba
Specifies the RBA of the VIR in the VTOC index that contains a structure error indicated by code.
secno
Specifies the section number in the VIER containing the VTOC index entry, if the VIR is a VIER.
offset
Specifies the offset into the section of the VTOC index entry, if the VIR is a VIER.