Owner's manual

Nomadic Disk Manager Interface
ServerNet Nomadic Disk User’s Guide—425485-001
7-17
SQL Command
SQL Command
Do not use the SQL command.
STATUS Command
Use the STATUS command to list the current ownership status of a segment or
segments. The status of a segment is an indication of its current ownership, rather than
an indication of the accessibility of its member volumes.
SEGMENT { segname | * }
indicates which segments are affected by the STATUS command. You can specify
the volumes in a specific segment (segname) or all volumes in all segments (*).
If you do not include the SEGMENT parameter, the volumes in the current segment
are affected. Each segment usually has four paths defined, although some segments
might have only one or two.
Considerations
Each path in a segment definition has a switch card associated with it. Each path also
has a switch setting definition, indicating ownership. The STATUS command
interrogates the current switch setting of each switch card associated with the segment
and reports one of the following results:
•
OWNED
If all the current switch settings for the segment match the defined ownership
settings, the segment is considered OWNED by this node.
•
NOT OWNED
If all the current switch settings are opposite of the defined ownership settings, the
segment is considered NOT OWNED by this node.
•
UNKNOWN
For any other permutation of switch settings, the ownership of the segment is
considered UNKNOWN. Although UNKNOWN is not necessarily bad, it is an
exception condition. A segment might be owned by the interrogating node, but a
switch module, for some reason, might not be accessible. In this case, the setting of
the Switch Cards in that switch module cannot be determined, and the status would
be reported as UNKNOWN.
The volumes in the segment might be accessible in spite of the inaccessibility of the
switch module. A switch card is passive; it does not need power to pass the signals
through to the disk module. It does, however, need power to respond to STATUS
and SWITCH instructions.
STATUS [ , SEGMENT { segname | * } ]