Catalogs are VSAM data sets, but VSAM recognizes, catalogs, and manages access to them in a special way. Converting catalog reserves can reduce contention caused by catalog activity. Depending on your system configuration, you need to do the following to convert catalog reserves:

1. To avoid a data integrity exposure, verify that all systems using a catalog are part of the complex.
2. Place a generic entry for SYSIGGV2 in the RESERVE conversion RNL.

   Do not place an entry for SYSIGGV2 in the SYSTEM inclusion RNL. Every SYSIGGV2 request that needs the SYSTEMS attribute already has it. Placing an entry for SYSIGGV2 in the SYSTEM inclusion RNL can degrade performance.

3. If you have catalogs used by any systems that are not part of the complex, you must place specific SYSIGGV2 entries for these catalogs in the SYSTEMS exclusion RNL. The catalog name must be either 20 bytes or 44 bytes in length depending on the name of the catalog. When the catalog name is 20 bytes or less, the RNAME must be 20 characters in length. When the catalog name is greater than 20 bytes, the RNAME must be 44 bytes. The RNL TYPE must be SPECIFIC.
   For example, specify one of the following depending on the length of the catalog name:

   RNLDEF RNL(EXCL) TYPE(SPECIFIC) QNAME(SYSIGGV2)
   RNAME('your.short.name.cat ')

   RNLDEF RNL(EXCL) TYPE(SPECIFIC) QNAME(SYSIGGV2)
   RNAME('your.longer.than.twenty.byte.catalog.name ')

   The second entry in the exclusion RNL for each catalog that is used by systems that are not part of the complex must be 88 bytes in length, a pattern entry with the first 44 bytes entered as question marks followed by the catalog name padded with spaces for the second 44 bytes of the entry. For example, the second entry using the catalog names from the previous example:

   RNLDEF RNL(EXCL) TYPE(PATTERN) QNAME(SYSIGGV2)
   RNAME('????????????????????????????????????????????your.short.cat.name')    

   RNLDEF RNL(EXCL) TYPE(PATTERN) QNAME(SYSIGGV2)
   RNAME('????????????????????????????????????????????your.longer.than.twenty.byte.catalog.name') 

   See the GRSRNLxx parmlib member in z/OS MVS Initialization and Tuning Reference for more information on defining the RNLDEF statement.
4. IBM® recommends SYSZVVDS and SYSVTOC entries be in the same global resource serialization RNL as either both converted, or both excluded. They must be converted in order to utilize the re-indexing of online volumes function.
5. SYSZBNDX uses the following rnames:
   • volser
   • ICKDSF HELD
   • volserRESERVE.
   Rnames volser and ICKDSF HELD are regarding global ENQs and should not be in the SYSTEMS exclusion RNL. The volserRESERVE rname is regarding a RESERVE, and so normal RESERVE considerations apply; the installation should determine if the re-indexing of online volumes function could apply outside the complex and either add an entry to the SYSTEMS exclusion RNL or the conversion RNL to avoid double serialization.