Instruction manual

CHAPTER 8. SYSTEM BACKUP FOR DEFINITY G3r
Command Operation
When an incremental backup is performed, the following procedure governs this operation.
Before each file is copied from the disk to the tape, the file on the tape is marked as “bad.”
When the file has been completely copied over to the tape, the file is then marked as “good” on
the tape. This process ensures that if the system were to reboot in the middle of this operation,
files in the process of being copied will not be usable (on the tape) because they will still be
marked as “bad.”
When a full backup is performed, the following procedures are used. When the process begins,
all files on the tape are marked as “bad.” When the entire disk has been copied, the files on the
tape will be marked as “good.” The only exception to this is that a file which is marked as “bad”
on the disk will retain this marking on the tape also.
When the backup is performed on both processors, the operation is performed in parallel. If the
backup operation fails on one processor the backup operation will proceed on the other proces-
sor.
The success or failure of the backup operation for each processor wili be displayed on the
screen, as shown below.
Processor
SPE_A*
SPE_B*
Backup Disk
Command Completion Status
success/specific error message
success/specific error message
* In a simplex system, only the active (default) SPE status is given. In a duplex system, if a qualifier is
used to select backup disk for only one SPE, only that SPE’s status is given.
FIGURE 8-2. Backup Completion Station
The following operational rules apply to the backup command:
1.
2.
3.
The
backup command will only be allowed if there are no other applications currently
using the MSS devices (E3).
The options entered by the user are validated against the system configuration and the
target devices for the backup command are determined (E11).
The disk must be in service (E13). The tape must be in service (E14).
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