🚀 go-pugleaf

I am posting this for a shop down the road. They have just gotten some
3380 model K disks on a 3380-23 controller, running VM/SP REL 5 (they
are moving to VM/ESA soon) on an IBM 9000 model 9210. They are running
VMBACKUP 4.1. They moved minidisks from some model A 3380's to the K by
using VMBACKUP, editing the directory to change the volume serial number for
some of the model A's, and changing both the volume serial number and
cylinder address for others, so they put two single-density volumes on one
double density one. The model K disks were prepared for the move by
the INSTALL command of DSF, followed by the CPVOLUME format and allocate
to set cylinder 0 and the allocation map (all PERM).

Everything went fine. The minidisks are quite usable. There is, however, one
slight problem. On some of the non-CMS (VSAM or VSE) minidisk VMBACKUP gets
an error on attempting a backup. The errors are fairly, but not completely,
repeatable. The errors occur both on minidisk whose cylinder addresses have
changed and those which have not changed. DDR gives no problems on reading
the minidisks, nor does the EREP log show any errors.

Does anyone have any ideas as to what the problem might be?