clearing effects - objects that could be cleared

Elliott, Robert Robert.Elliott at
Fri Mar 1 11:16:56 PST 2002

* From the T10 Reflector (t10 at, posted by:
* "Elliott, Robert" <Robert.Elliott at>
Here are some things affected by hard resets that are possibly affected
by logouts.  References are to SPC-3 revision 4 unless otherwise noted.

Mentioned by FCP-2 clearing effects table (FCP-2 revision 7 section 4.9):
* classic reservations released (5.5.2, 7.26.2, 7.26.3)
* shared mode pages reset to default/saved values (7.9.2, 7.9.6)
* non-shared mode pages reset to default/saved values (7.9.2, 7.9.6)
* Prevent Allow Medium Removal state set to "allow" (7.13)
* Buffered data for EXTENDED COPY cleared (e.g. COPY STATUS data,
  RECEIVE DATA data, FAILED SEGMENT DETAILS data)(7.16.2, 7.16.3, 7.16.5)
* Buffered data for XOR commands cleared (SBC-2
* AccessID enrollment state forced to pending-enrolled (future SPC-3)
* preexisting ACA, unit attention, and deferred error 
  conditions cleared (FCP-2)

Not mentioned by FCP-2 clearing effects table:
* log pages reset (7.6)
* Alias list associations (7.2.1)
* Generation value for persistent reservations set to 0 (7.11.3)
* Download microcode mode for WRITE BUFFER (7.33.5-8)
* Self-test cancelled (8.2.9)
* Power condition state (8.4.11)
* allowed to clear interval timer and report count 
  fields in Informational Exceptions mode page MRIE field (8.4.10)

This is the wording in SSC-2 revision 7 section 8.3 preventing
clearing of important mode pages for tapes:
"The device-specific parameters contained in the mode parameter
header, mode block descriptor values, and data compression page 
shall be retained following a reset condition (e.g., Target Reset, 
SCSI Logical Unit Reset, Fibre Channel Reset LIP or PLOGI)."

SSC-2 clears these on hard resets:
* software, associated, persistent, and permanent write protect bits 
  in the device configuration mode page (
* TapeAlert flags (

Rob Elliott, Compaq Server Storage
Robert.Elliott at

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