1 :Info: mrds.recovery.gi: mrds.recovery:  1980-05-14  mrds.recovery
 2 
 3 Function: This is a description of the procedure for backing up mrds
 4 databases and then recovering to that earlier state of the database.
 5 
 6 
 7 Procedure: To obtain the backup copy of the database, do a
 8 quiesce_mrds_db on the current database, then do a copy_dir of the
 9 database directory into another part of the storage hierarchy, and
10 finally do quiesce_mrds_db with the -free option on the original
11 database.
12 
13 
14 To return to the earlier state of the database that has been backed
15 up, do a quiesce_mrds_db of the current database, delete that
16 database with a delete_dir, do a copy_dir of the backup copy into the
17 original storage location, then finally do a quiesce_mrds_db with the
18 -free option on the new current database.
19 
20 
21 Notes: The quiescing process is the only process that can open or
22 update the backup copy of the database.
23 
24 The backup copy can be freed from the quiescent state if it is to be
25 used for program development, rather than as a static backup copy.
26 
27 Recovery of a database quiesced by a dead process requires two
28 commands: quiesce_mrds_db path -free
29           adjust_mrds_db path -trouble_switch off
30 However, there is danger of an inconsistent database.
31 
32 If display_mrds_db_status shows many open users, a long wait time may
33 be needed for quiesce_mrds_db.  However, a short wait time will work
34 as a go/no_go test.  Also, dmdbs will show if the database is in a
35 quiescent state.
36 
37 
38 :hcom:
39 /****^  HISTORY COMMENTS:
40   1) change(2020-12-15,GDixon), approve(2021-02-22,MCR10088),
41      audit(2021-05-27,Swenson), install(2021-05-27,MR12.6g-0056):
42       A) Fix errors reported by the new verify_info command.
43                                                    END HISTORY COMMENTS */