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Data can be recovered from disks by using DISCUTIL in conjunction with the RECOVER command of VOLUTIL. This section describes two data recovery tasks: Saving files to tape using DISCUTIL. Recovering files to disk using VOLUTIL.
Saving Files to Tape | |
Saving files to tape allows you to save data that you cannot access because the disk has failed, the system has failed, or a directory has become corrupted. The DISCUTIL SAVE command is used to save files. Example: Saving Files to TapeThis example shows how to save disk files to tape using DISCUTIL. Enter the SAVE command at the discutil prompt. Enter the file set you want saved at the prompt.
discutil>SAVE
ENTER FILE SET TO BE SAVED: MYFILE.JOHN.SMITH
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Use the filename.groupname.acctname syntax where: - filename
is the file designator. The file(s) must reside on a disk defined during startup of
DISCUTIL or with the DISCUTIL CONFIGURE command.
Refer to chapter 5 for more information on this command. - groupname
is an optional group
designator. - acctname
is an optional account designator.
If you press RETURN without entering a file set, DISCUTIL ends the SAVE command. The parameters filename, groupname, and acctname may be replaced by @ to signify "all members of the set". For example, @.@.MPEXL, @.UTIL.MPEXL, or @.@.@. @.@.@, @.@, and @ are equivalent. The prompt is repeated after the file set is saved. To terminate SAVE, press RETURN. Enter RETURN at the prompt below to indicate that "no" hierarchical directories are saved.
TRAVERSE DIRECTORIES UNDER FILESET (Y/N)?
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Enter the LDEV at the prompt. To save files from a particular logical device (disk), enter the LDEV now. SAVE searches only the specified disk for the file(s) you want to save. You may also press RETURN at this prompt to indicate you want SAVE to search each LDEV for file(s). The LDEV entered must be one that is known to DISCUTIL. Use the PDEV command to determine if an LDEV is valid. Refer to chapter 5 for more information on this command. The SAVE command prompts you for a volume set name if you did not specify an LDEV number. The volume set's name is the name of the volume set you want to save. If a volume set name is not given, DISCUTIL saves the file sets from all disks. If you enter an LDEV, DISCUTIL will not prompt for a volume set.
ENTER THE VOLUME SET NAME: PROD_SET
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Enter the volume set's name if you want SAVE to search for file(s). The volume set's name must be known to DISCUTIL. Use the PDEV command to determine valid volume set names. You may also press RETURN to indicate you want SAVE to search all disks for the file(s). Enter the modification date at the prompt.
ENTER THE MODIFICATION DATE (MM/DD/YYYY): 04/01/1989
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Only files modified since this date are saved to tape. DD is a two-digit number for the day of the month, MM is a two-digit number for the month, and YYYY is a four-digit number for the year. Omit the date specification and press RETURN at the prompt to save all files requested. Figure 4-1 Modified Files Saved
discutil> SAVE
WARNING BLOCK
ENTER FILE SET TO BE SAVED: MYFILE.JOHN.SMITH
TRAVERSE DIRECTORIES UNDER FILESET (Y/N)?
ENTER THE LDEV: 17
ENTER THE MODIFICATION DATE (MM/DD/YYYY): 04/01/1989
ENTER THE TAPE LDEV 7
MYFILE.JOHN.SMITH - LDEV 17 - ADDR $0002CA0 - FOUND
MYFILE.JOHN.SMITH - LDEV 17 - ADDR $0002CA0 - SAVED
WARNING BLOCK
ENTER FILE SET TO BE SAVED:
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DISCUTIL now searches each LDEV specified for the designated file(s). Each time a file is found a message is printed. When the file is successfully written to tape another message is printed. Errors are also reported. If the end of a tape is reached, DISCUTIL prompts to mount a new tape. Once a tape is mounted, the save continues until all specified files are written. Enter the TAPE LDEV: ldev After all specified files are saved, the ENTER FILE SET TO BE SAVED: prompt is displayed and you may specify additional files.
To Make Multiple TapesetsTo make multiple tapesets, the current SAVE command must finish with the current tapeset. To do this, type RETURN at the ENTER FILE SET TO BE SAVED: prompt. This returns you to the DISCUTIL> prompt, and the following message displays.
MANUALLY REWINDING THE TAPE DRIVE AND STARTING A NEW TAPESET
BEFORE THE CURRENT SAVE COMMAND IS COMPLETE WILL CAUSE FILES TO BE LOST!!!
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Example: Making Multiple FilesetsThis example shows how to make multiple filesets. Invoke SAVE. The system displays the following:
WARNING!!!
MANUALLY REWINDING THE TAPE DRIVE AND STARTING A NEW TAPESET
BEFORE THE CURRENT SAVE COMMAND IS COMPLETE WILL CAUSE FILES TO BE LOST!!!
PRESS RETURN AT "ENTER FILE SET TO BE SAVED:" TO COMPLETE THE SAVE
PROPERLY. SEE HELP ON SAVE.
ENTER FILE SET TO BE SAVED: @.@.@
TRAVERSE DIRECTORIES UNDER FILE SET (Y/N)? RETURN
ENTER THE LDEV: RETURN
ENTER C RETURN TO CONTINUE
ENTER THE VOLUME SET NAME: RETURN
ENTER THE MODIFICATION DATE: RETURN
ENTER THE TAPE LDEV: 7
ENTER FILE SET TO BE SAVED: RETURN
:
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Tape Errors During a DISCUTIL SAVEIf a tape ends in the middle of a file, the rest of the file will be saved on the next tape. If a tape write error occurs, DISCUTIL resaves all files on the bad tape to a new tape. If part of a file is on the previous tape, then the entire file is resaved on the new tape. DISCUTIL marks a tape anytime it cannot save an entire file. The VOLUTIL RECOVER command aborts the recovery of that file when it reads the mark on a file. It then continues with the next file. DISCUTIL is terminated by using the EXIT command. Control then returns to the system and the system prompt is displayed. Recovering Files to Disk | |
VOLUTIL's RECOVER command recreates files from the output tape produced by DISCUTIL. You will need SM, system manager, capability to use the VOLUTIL RECOVER command. Example: Recovering Files to DiskThis example shows how to recover disk files from tape after the operating system has been successfully restarted. Load the tape that contains the files you want to recover. Invoke VOLUTIL. Use the RECOVER command with the NOKEEP option to start the copy. The NOKEEP option replaces files on the disk with files of the same name on the tape. As each file is copied to the disk, messages are displayed. The system will prompt you to mount the next tape if the files continue onto additional tapes.
volutil: RECOVER;NOKEEP
(fname) (group) (acct) IS RESTORED
TEXT .PROD .MANUF IS RESTORED
INTRO .PROD .MANUF IS RESTORED
VOLM2 .PROD .MANUF IS RESTORED
END OF VOLUME, RECOVER DONE
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