CopyWrite may be used to restore non-resident files, using the CATALOG to select the best file to restore, based on the cycle, version and timestamp of the file entries.

Rules

• The syntax is the same as a Library/Maintenance COPY statement.
• The<source volume> name (FROM part) specifies the volume with which the non-resident entries are associated.
• There may be multiple <copy from group> parts, but they must all specify the same <source volume attribute list>.
• The <source volume attribute list> must have these attributes (KIND=CD,HOSTNAME=LOCAL,USECATALOG). TheKIND and HOSTNAME attributes are used to select COPYWRITE, and the USECATALOG attribute tells COPYWRITE that this is a restore of files from theCATALOG.
• If there is a resident entry on the volume with which the non-resident entry is associated, the file will not be restored, even if the <destination volume>is a different volume. The reason is that it is better to copy the resident entry.
• The <destination volume> need not be the volume with which the resident entry is associated. That is to say, the file may be copied TO any other volume.
• The file may be copied AS another filename.
• The best file to restore is the file with the best genealogy.
• CopyWrite minimizes the number of volumes which must be loaded, and batches together the files to be restored from the same volume. It selects OnLine volumes in preference to OffLine volumes.

A Method for Maintaining Release Files

This is a method for maintaining the UNISYS release files using CopyWrite and the Catalog.

• Create a temporary volume for the release, and add it to the volume library.
  RC PK 507 NAME=RELEASE471 SERIAL=471000
  VOLUME ADD RELEASE471(PACK,SERIALNO=471000)
  
  
• Copy and Catalog the files from each of the releaseCDs to NULL. Make up aSERIALNO for the <source volume>, and specify on the <destination volume>the FAMILYOWNER as the temporary volume. Each file on the CD will have a non-resident entry added to the volume, with a backup reference to the CD, however, the file will not actually be copied.
  COPY&CATALOG *= FROM SYSTEM_47150(CD,SERIALNO="CD4701") TO NULL(CD,HOSTNAME=LOCAL,FAMILYOWNER=RELEASE461);
  
  COPY&CATALOG *= FROM SYMBOL_47150(CD,SERIALNO="CD4702") TO NULL(CD,HOSTNAME=LOCAL,FAMILYOWNER=RELEASE461);
  
  Do the same for all the release CDs and also any A-Tapes and Interim Corrections. Even though the same files exist on the A-Tapes and Interim Corrections, the Catalog creates a new entry in the Catalog because the files have a different genealogy, that is, they have a different cycle or version or timestamp. Since CopyWrite always restores the 'best' version, the latest version of the software is selected, and the backup reference specifies the CD volume on which the file may be found.
• After all the CDs have been copied, the temporary volume can be reconfigured to another name, since the Catalog retains the information for the non-resident volume.
• There are several methods available to find out on which volume a software item is located.
• The first method is to use the PD command from the ODT. The response contains the file entries and the volume serial number on which each entry may be found.
  
  PD *SYSTEM/PASCAL ON RELEASE471
  
  The name of the volume may be found using the Serial Number of the volume,
  
  PV PK CD4702
  
• FLEX can be used to select files on the non-resident volume, by performing a LINEAR pass of the Catalog. There are several file attributes for non-resident entries which may be used for selection.
  
• CopyWrite may be used to restore the files from the backup media to some volume,
  
  COPY *SYSTEM/PASCAL FROM RELEASE471(CD,HOSTNAME=LOCAL,USECATALOG) TO SUPPORT(PACK)