GRASS VALLEY M-Series, Руководство по обслуживанию

Страница: 36 / 80

36
M-Series Service Manual 6 July 2004
Chapter 2 Troubleshooting problems
Checking the storage system
The following section provides guideline for investigating problem areas related to
the storage system. Use this section if you have problems with media input and/or
output that are intermittent or seem to be related to certain usage patterns.
Problem Possible Causes Corrective Actions
Symptoms can include
black video recorded or at
playout, frozen video, slow
performance, or
inconsistent media access.
These symptoms can be
accompanied by Status
Pane messages regarding
disk problems or overrun/
underrun conditions for
encoders, decoders, or
timecode. The following causes can occur on
their own or in combination to
produce the problem:
Disk oversubscription — This
occurs when requests to the media
disk exceed the disk’s bandwidth
capabilities. This generally occur in
extreme cases when a combination
of high-bandwidth operations are
taking place, such as jog/shuttle,
record/play on multiple channels, or
streaming multiple clips.
High CPU activity in Windows —
This occurs when activities on the
Windows operating system over-tax
the capabilities of the motherboard
processor. This commonly happens
when unsupported software has been
installed that competes with iVDR
applications. Virus scanners and
screen savers can cause this type of
problem, since they can start
automatically and consume system
resources.
Encoder overrun — This occurs
when an encoder is flooded with
more data than it can process within
its real-time requirements for
recording.
Decoder underrun — This occurs
when a decoder is starved for data
and cannot deliver enough to satisfy
real-time requirements for playout.
Disk faults — This occurs when a
media disk is severely fragmented or
has a bad blocks that interfere with
some, but not all, media operations.
For example, a particular clip can be
written on a bad block, so the
problem occurs only on that clip. Try to re-create the problem.
Identify all the interactions that
affected the system and run all
the same operations as when the
error occurred. Record/play/
stream the same clips.
Investigate the functions that
seem to push the system into the
error state. If you determine that
certain simultaneous operations
cause the problem, re-order your
workflow to avoid those
situations. If you determine that
the problem is only on certain
clips, investigate disk faults.