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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

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:

• The name of the backup volume
• The name of the save set that contains the file you want
• The name of the client to which the file belongs
• The date and time the file was backed up

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 re-introduce 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 place 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 backup volume may contain files for a client, but will be recovered 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.

You could also use rsh (or its equivalent) in conjunction with the following command in order to recover the save set to the client, if the save set originated on a LSM client instead of the LSM server.

scanner -s ssid device-name | rsh client "(cd destdir; /pathto/uasm -rv)"

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 (such as backup tapes, optical disks, or files) 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 ] 

• Use the -b pool option to specify the pool that the volume should belong to. This option only applies to volumes backed up by versions of LSM that did not store pool information on the media.
• Use the -B option, without the -S option, to quickly scan the tape to the location of the start of the bootstrap save sets. When the entire tape has been scanned, the save set ID and tape file location of the most recent bootstrap save set is printed to standard output.
• Use the -c client option to instruct scanner to only process save sets that came from the machine specified by client. You can specify more than one client name in the same command line. The -c option can also be used in conjunction with the -N option, but only if the -i or -x option are also specified.
• Use the -f file option to start the scan at a specific media file number.
• Use the -i option to instruct scanner to rebuild both the client file indexes and media database from the volumes that are read. If you specify a single save set with the -S ssid option, only the entries from the specified save set are made to the client file index.
• Use the -m option to instruct scanner to rebuild only the media database for the volumes that are read.
• Use the -n option to run scanner without rebuilding the client file indexes or media database. This option provides a way to check the media without modifying the client file indexes or media database.
• Use the -N name option to process only save sets that match the specified name. The value of name should be a literal string. You can specify multiple names when this option is used in conjunction with the -c client option, but only if the -i or -x option are also specified.
• Use the -p option to print out information about each save set as it is processed.
• Use the -q option to only display error messages or messages of significance.
• Use the -r record option to start the scan at a specific media record number, to avoid a scan of potentially unused information.
• Use the -s server option, when you run the scanner program on a storage node, to specify the controlling LSM server.
• Use the -S ssid option to extract the save set specified by ssid. When this option is used in conjunction with the -i or -x options, you can specify multiple ssid values. The save sets selected are in addition to any selected by the use of the -c and -N options. If the -B option is also specified, the value of ssid is assumed to be that of the bootstrap save set; only one ssid can be specified in this case.
• Use the -x command option, with an optional list of command arguments, to specify a UNIX command to execute on each save set scanned. This option can only be specified once per scanner command line, after the device specification.

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 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) 

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:

• Rebuild the media database entries for everything on the storage volume (by executing scanner -m device) and perform a save set recovery.
• Rebuild the media database and client file index entries for everything on the storage volume (by executing scanner -i device) and perform either a save set recovery or a client file index-based recovery.
• Rebuild the media database entries for a specific save set on the storage volume (by executing scanner -s save-set-id -i device) and perform a save set recovery.
• Rebuild the media database and client file index entries for a specific save set on the storage volume (by executing scanner -s save-set-id -m device) and perform either a save set recovery or a client file index-based recovery.
• Execute scanner with -c client-name and -N save-set-name options, along with any other of the options previously described to further specify the save sets by client or name.
• Execute scanner -s save-set-id to send a specific save set to standard output.
• Use the scanner program's -x option to introduce further processing commands on a per save set basis.

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