TFDS Manual

Using TFDS
Tandem Failure Data System (TFDS) Manual—520628-003
2-3
When to Use TFDS
4. TFDS automatically initiates a processor dump (if AUTODUMP is enabled). The
dump can be backed up to tape (optional).
5. TFDS automatically reloads the processor (if AUTORELOAD is enabled).
6. After the failure data is captured, TFDS builds a software failure event and writes it
to the Event Management Service (EMS) log (whether the failure event was unique
or recurrent). For required follow-up actions, see What to Do After a Software
Failure on page 2-6.
When to Use TFDS
Because the TFDS process ($ZDMP) must be running when a software failure event
occurs to utilize most TFDS services, it should be running at all times. TFDS lets you
gather information with little or no impact on the production environment. TFDS takes
no processor time to constantly monitor your system. It is awakened only when action
is necessary. Processing an RCVDUMP has the most impact on system performance.
(For a caution about allowing more than one concurrent dump, see the following
subsection, System Resource Usage.)
Even if you do not plan to use the automated data collection and recovery features,
you should keep running TFDS at all times in order to process TFDS software
instrumentation calls issued by many NonStop Kernel subsystems.
If TFDS is not running when a software-related processor failure occurs, the TFDS
TFDRTL still reports the software failure event to the EMS log (so you might get TFDS
events even when TFDS is not running), but you cannot suppress duplicate dumps or
keep dump records in an orderly fashion.
For more information on how to start and manage TFDS on your particular system, see
Section 3, Starting and Configuring TFDS.
System Resource Usage
CPU DOWN messages, instrumentation calls, and TFDSCOM dump requests trigger
TFDS memory dumps. TFDS can accept several dump requests simultaneously, but a
dump request for a specific processor is not valid if a previous request for that
processor is still pending.
Disk Space
Because of the size of the related dump files, disk space is an important consideration
when you use TFDS, especially if any processors have memory sizes of 16 gigabytes.
Prior to the FMD enhancement to TFDS (see Appendix F, Fast Memory Dump), TFDS
obtained disk space one of two ways:
•
It used the volume specified in DUMPVOLUME.