This is currently covered by ADC section 4.2.6 and ADC-2
Rev 8 section 4.6.
From ADC-2:
4.6 TapeAlert application client
interface
The ADC device server supports a modified version of
TapeAlert specified in SSC-2. As supported by the ADC device server, the
TapeAlert flags represent states, and the state flags are not set to zero upon
retrieval of the TapeAlert Response log page (see 6.1.3). Instead, the state
flags are set to zero upon a change of the condition involved with the state
(see table 5).
-roger rose
Product Test, Tandberg Data
In reviewing Michael Banther's
proposal for tape alert flag (06-420r2), it occurred to me that there is a
problem with SMC tape alerts in general if ADI bridging is being used for host
access to the library.
smc3r09
clause 5.2.2 third paragraph defines deactivations for tape alerts. Numbered
list 1) states "after the TapeAlert log page is
read. The TapeAlert flags shall be deactivated on a per-initiator basis such
that active flags are available for other initiators; ".
and
in proposal 06-420r2 clause 5.4.4 last paragraph, the same statement is made
with "should" instead of "shall".
Since a library device using ADI bridging is not aware of initiators, the
library cannot clear the flags on a per initiator basis. Does this mean the DT
device must cache the tape alert log page and keep track of the reads of that
log page? If so, how does the DT device know when to cache a new page? And if
the DT device handles the tape alert log page on a per initiator basis, how does
the library know when to clear the flags? As far as I can tell, there is no
mechanism to handle this.
Even if
proposal 06-420r2 is not incorporated into smc3, the problem still
exists.
regards,
Geoffrey L. Barton
Overland
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