1 11/06/89  poll_mpc
 2 
 3 Syntax as a command:  poll_mpc {mpc_list} {-control_args}
 4 
 5 
 6 Function:  initiates and controls automatic polling of MPCs.  Polling
 7 consists of reading statistics on device usage and errors from the MPC
 8 memory and logging it in either the syserr log or a file.  If an error
 9 condition is detected, a message is entered in the syserr_log with a
10 code of 3.  This sounds the bootload console alarm and prints the
11 message in the bootload console log on a normally configured system.
12 This command sets up timers and event call handlers within the process.
13 Once initiated, MPC polling is performed periodically, independent of
14 whatever else is going on in the process.  This command is used by the
15 initializer or a daemon; Utility.SysDaemon is recommended.
16 
17 
18 Arguments:
19 mpc_list
20    is a list of the names of the tape or disk MPCs to be polled.  If no
21    names are listed, all tape and disk controllers are polled.
22 
23 
24 Control arguments:
25 -debug, -db
26    prints extra debugging information each time polling is performed.
27 -log
28    writes statistical information to the syserr log.  Access to the
29    hphcs_ gate is required.  This is the default.
30 -output_file path, -of path
31    writes statistical information to the segment specified by path.
32    This report is the same as the one generated by the -stat control
33    argument of the dump_mpc command.  This control argument can be used
34    in conjunction with -log.
35 -time N, -tm N
36    specifies the polling interval in minutes.  The default polling
37    interval is 15 minutes.
38 
39 
40 The following control arguments modify the polling already in process
41 and cannot be used on the initial invocation of the poll_mpc command.
42 -finish
43    schedules the last polling cycle immediately.  Once this cycle
44    completes, polling is disabled, and a new poll_mpc command is
45    required to start it again.  To stop polling without performing one
46    last cycle, use both -stop and -finish.
47 -start, -sr
48    resumes polling for the MPCs specified with the mpc_list argument.
49    If no MPCs have been specified, polling of all MPCs is resumed.
50    Note that the next polling does not occur immediately; it is
51    performed during the next scheduled polling cycle.
52 
53 
54 -stop, -sp
55    stops polling for the MPCs specified with the mpc_list argument.  If
56    no MPCs have been specified, polling of all MPCs is stopped.
57    Polling continues to be scheduled periodically, even though no MPCs
58    are being polled.
59 
60 
61 Notes:  If polling of an individual MPC fails three consecutive times,
62 either because it cannot be attached or because of I/O errors, polling
63 of that MPC is stopped.  If three consecutive scheduled polling cycles
64 are missed because a previous cycle did not complete, an automatic
65 finish operation is performed, and no further cycles are scheduled.
66 
67 When the system is reconfigured to add an MPC, if you want that MPC to
68 be polled you must issue "poll_mpc <mpc_name> -start".
69 
70 Polling of MPCs has no effect on the users of devices connected to the
71 MPC.