Instruction manual

CHAPTER 8. SYSTEM BACKUP FOR DEFINITY G3r
Invoking the
restore
command with the
standby
option causes files from the tape associated
with the standby processor to be copied to the disk on that same processor.
Invoking the
restore
command with the
both
option forces the system to copy files from the
tape-to-disk device on both mass storage systems concurrently. If the standby processor is inac-
cessible, the command will fail on both processors. This means that no data will be written on
either of the specific processors. The default in a duplex system is
both.
Invoking the
restore
command with the
either
option forces the system to copy files from tape to
disk device in both mass storage systems concurrently. If the standby processor is inaccessible,
the command will still execute on the active processor and files will be copied to the disk.
Invoking the command with the
incremental
option causes a selective restore operation to be
performed. in this case, all files on the tape that are marked as “good” and which have a newer
last file update time than the corresponding disk files, are copied to the disk. Not copying files
marked as “bad” ensures that corrupted files do not overwrite good (but possibly older) files. The
default value is
full.
If a
full
disk restore is specific, the entire contents of the tape are copied to the disk. All files,
“good” and “bad,” regardless of the last file update times, are copied to the disk.
Command Operation
For an
incremental
restore, the files are copied in the following manner. Before each file is
copied from the tape to the disk, the file on the disk is marked as “bad.” When the file from the
tape has been completely copied over onto the disk the file is then marked as “good” on the
disk. This process ensures that if the system were to reboot in the middle of the operation, files
in the process of being copied will not be usable because they are still marked as “bad.”
For a
full
restore operation, the files are copied in the following manner. When the process
begins, all files on the disk will be marked as “bad.” When the entire tape has been copied to
disk the files on the disk will be marked as “good.” The only exception to this is that a file which
is marked as “bad” on the tape will retain this marking on the disk also.
The success or failure of the command for each processor will be displayed on the screen, as
shown below.
Restore Disk
Processor
Command Completion Status
SPE_A*
success/specific error message
SPE_B*
success/specific error message
FIGURE 8-4. Restore Completion Status
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