DMOH0104E CHECK(DMO_TAPE_LIBRARY_INIT_ERRORS) determined that library device initialization errors occurred during IPL.

Explanation
 During IPL, tape devices that have connectivity
to the system are initialized. Initialization involves doing I/O to
each device to determine if the device is in a library, and if so
which library (and which port within  the library).
 When errors
are detected during initialization they are recorded for diagnostic
purposes and are reported by message IEA438I. The errors can also
be displayed by the DEVSERV command DS QL,IEA438I, as well as by the
DMO_TAPE_LIBRARY_INIT_ERRORS health check.
 The following errors
may be reported:

                                      Library interface is offline
The hardware communication path between the tape control unit
and the library manager has not been established. 
Returned a zero library-id
The hardware communication path between the tape control unit
 and the library manager has been established, but the library manager
returned an incorrect library-id (zeros) to the host.
Unavailable to library manager
The hardware communication path between the tape control unit
and the library manager has been established, but the library manager
has 'marked' the device unavailable.
HCD-DEVICE libid/portid error
During device initialization, it was found that the LIBRARY-ID
and LIBPORT-ID specified to HCD do not match the LIBRARY-ID and LIBPORT-ID
that were assigned to the hardware during installation.
EPI does not match pool EPI
The ERDS Physical Identifier (EPI) of the device is not the same
as other devices in the same pool. All of the devices in a pool must
be the same type. A 'pool' refers to all of the devices attached to
the same PORT in the library.
I/O error (probable timeout)
The I/O used to perform device initialization ended with an error.
The most likely error during IPL is a timeout which can occur because
I/O is strictly timed during IPL
Unkown error type
An error other than the expected error types caused device  initialization
to fail. 

System action
 The system continues processing.
 If
the device was intended to be brought ONLINE during IPL, the device
will NOT be ONLINE.

Operator response
 Report this problem to the system programmer.

System programmer response
 Attempt to VARY the device ONLINE.
If the problem still exists message IEA437I will be issued with a
detailed explanation of the error.

Problem determination
 Refer to message IEA437I.

Module
 DMOHC001

Source
 DFSMS Device Manager Health Checker

Reference Documentation
 Messages IEA437I
and IEA438I. Refer also to DEVSERV QLIB in z/OS MVS System Commands.

Automation
 N/A

Routing Code
 See note 35.

Descriptor Code
 12 is the default set by this check. See note 1.