Legato Storage Manager Administrator's Guide
Release 8.1.5

A68160-01

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Scanner

Scanner on UNIX

Save Set Recover and Scanner

Use save set recover to recover backed up data that has passed the period of its browse policy but is still in the media database. Save set recover can be initiated either from the command line by executing the recover program and providing specific save set identification numbers (ssid) as options, or from the LSM administration program (nwadmin). Individual files or directories can be specified by including the exact path along with the ssid. Permission to perform a save set recovery is granted only to root.

Use save set recover only when the entries have been removed from the online file index (when the save set has passed its browse policy). When you perform a save set recover, you must recover the level full backup first, then recover the other backups in level order, 1 through 9, then recover the incremental backups.

Use the scanner program to re-create client file index entries or re-create media database entries, if no entries for the volume exist in the media database. The scanner program can read the storage volume directly, without assistance from LSM.

To find the volume that contains the file you want, use the mminfo program if the volume is still in the media database or the scanner program, if the volume is no longer in the media database. The mminfo and the scanner programs provide detailed information of the contents of the volume. This information includes:

How to Rebuild a Save Set Entry in the Client File Index

If the file is not browsable (which means that the save set's browse policy has expired), but its save set is still tracked by LSM in the media database (which means that the save set's retention policy has not expired), follow these steps to recover the save set's entry back into the client file index:

  1. Run the mminfo program:

    mminfo -a -v volume-name
    
    
  2. From the mminfo output, find the save set ID that you believe contains the file you want. Make sure it is not the bootstrap save set ID.

  3. Once you have the proper save set ID, replace the save set entry in the file index with the scanner program:

    scanner -i -S save-set-id device-name
    


    Note:

    If the save set spans volume boundaries, use the scanner program to read from all the volumes. Otherwise, the client file index will not be fully rebuilt, making it impossible to perform an online recovery of the files in this save set.  


  4. Use the LSM recover program to mark the file for recovery.

If the save set that contains the file is not browsable, and the save set is not represented in the media database, both the browse and retention policies have expired. Follow these steps to rebuild the save set's entry in both the client file index and the media database:

  1. Run the scanner program on the backup volume that you believe contains the file you want (make a guess based on the adhesive label on the volume).

    scanner device-name
    
    
  2. Use the output from the scanner program to decide whether to reintroduce the contents of this volume into the client file indexes and whether the save set you want to rebuild is on this volume. You must locate all of the volumes that contain this save set ID.

  3. Once you have determined which volumes to re-introduce into the online indexes, run the scanner command below:

    scanner -i device-name
    
    

    The scanner command asks for a new volume until you terminate it. To rebuild the indexes completely, you must scan in all of the volumes that contain the save set ID.

  4. Use the nwrecover program to browse the file index for the file you want to recover.

How to Recover an Entire Save Set to the LSM Server

To recover an entire save set directly to your disk volume, use the following options to invoke the scanner program:

scanner -S save-set-id device-name | uasm -rv

This command reads all the information associated with the save set ID from the volume and places a copy of this data on the LSM server in the exact way that it is stored on the backup volume. In other words, the scanner command recovers the save set specified by the save set ID number to the LSM Server's hard drive.

If you want to be sure this action is correct before you actually perform it, add the -n flag to the uasm command. The -n flag sends the output from scanner to /dev/null and lists all the filenames contained in the save set.

How to Recover One File Directly from a Volume

To recover a single file from a volume, run one of the following commands:

scanner -S save-set-id device-name | uasm -rv filename

or

scanner -S save-set-id device-name | uasm -rv -m source=dest filename

The -m option of uasm maps (relocates) the recovered file from the source to the dest (destination) directory.

Scanner

The scanner program directly reads LSM media (backup tapes) to confirm the contents of a volume, to extract a save set from a volume, or to rebuild the LSM online indexes. You can only run this command as root. You must specify a device, which is usually one of the device names used by the LSM server. If the device is a tape drive, it must be a nonrewinding type.

If the scanner program is invoked without options (or only the -v option), the volume on the specified device is scanned and a table of contents is generated. The table of contents contains information about each save set found on the volume. By default, one line of information is written to standard output for each save set found on the volume. The information provides the client name, save set name, save time, level, size, files, save set ID, and a flag.

The following example describes the format and options available for the scanner program:

scanner [ -Bimnpqv ] [ -s server ] [ -S ssid ] 
[ -c client ] [ -N name ] [ -f file ] [ -r record ]
[ -t type ] [ -b pool ] device [ -x command argument-list ]

Refer to the scanner(1m) man page for examples of scanner command usage and a list of common error messages.

The Scanner Program Requests an Entry for Record Size

If you use the scanner program with the -s option but without an -i or -m option, and you receive the following message:

please enter record size for this volume ('q' to quit) [xx] 

The number in the bracket [xx] is the entry from the last query.

The scanner command always rewinds the tape and reads the volume label to determine the block size. If the volume label is corrupted or unreadable, you will see a message asking you to enter the block size (in kilobytes).

Type in the block size; it must be an integer equal to or greater than 32. If you enter an integer that is less than 32, you receive the following message:

illegal record size (must be an integer >=32) 

The Scanner Program Marks a Volume Read-Only

When you use the scanner program to rebuild the index of a backup volume, the scanner program marks the volume read-only. This is a safety feature that prevents the last save set on the backup volume from being overwritten. To write to the media without marking it read-only, use the nsrmm -o command:

# nsrmm -o notreadonly volume-name

Scanner on Windows NT

Using the Scanner Program

The scanner program reads the volume directly, without accessing information that may be available in the media database. If no entries exist in the media database, you must take an educated guess at which volume contains the data to recover.

Mount the volume and execute the scanner command with any of its options. The most commonly used scanner options are as follows:

Detailed information about scanner program syntax and examples of how scanner options can be customized to meet the needs of a particular recovery situation are available in the help documentation regarding the scanner command line utility.

The entries placed in the client file index receive a status of "scanned-in" to protect them from automatically being deleted the next time the index management service checks the index for entries that have surpassed their browse policy. The entries placed in the media database also receive a status of "scanned-in" and the volume mode is listed as "read-only." These entries will need to be manually deleted.

Scanner

The scanner program directly reads LSM media (backup tapes) to confirm the contents of a volume, to extract a save set from a volume, or to rebuild the LSM online indexes. You can only run this command as root. You must specify a device, which is usually one of the device names used by the LSM server. If the device is a tape drive, it must be a nonrewinding type.

If the scanner program is invoked without options (or only the -v option), the volume on the specified device is scanned and a table of contents is generated. The table of contents contains information about each save set found on the volume. By default, one line of information is written to standard output for each save set found on the volume. The information provides the client name, save set name, save time, level, size, files, save set ID, and a flag.

The following example describes the format and options available for the scanner program:

scanner [ -Bimnpqv ] [ -s server ] [ -S ssid ] 
[ -c client ] [ -N name ] [ -f file ] [ -r record ]
[ -t type ] [ -b pool ] device [ -x command argument-list ]

The Scanner Program Requests an Entry for Record Size

If you use the scanner program with the -s option but without an -i or -m option, and you receive the following message:

please enter record size for this volume ('q' to quit) [xx] 

the number in the bracket [xx] is the entry from the last query.

The scanner command always rewinds the tape and reads the volume label to determine the block size. If the volume label is corrupted or unreadable, you will see a message asking you to enter the block size (in kilobytes).

Type in the block size; it must be an integer equal to or greater than 32. If you enter an integer that is less than 32, you receive the following message:

illegal record size (must be an integer >=32) 

The Scanner Program Marks a Volume Read-Only

When you use the scanner program to rebuild the index of a backup volume, the scanner program marks the volume read-only. This is a safety feature that prevents the last save set on the backup volume from being overwritten. To write to the media without marking it read-only, use the nsrmm -o command:

# nsrmm -o notreadonly volume-name




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