Resize (or move) DfRMM Journal Dataset

Ever wanted to resize the RMM Journal dataset? Ever wanted to do this without stopping RMM?

This is the short recipe for doing so:

1. Allocate your new journaldataset (DFRMM.NEW.JOURNAL)
2. Quiesce DFRMM (f DFRMM,quiesce)
3. Run EDGHSKP, PARM=(BACKUP) to empty the Journal
4. Rename current journaldataset
5. Rename DFRMM.NEW.JOUNRAL to whatever is in your EDGRMMxx (or change EDGRMMxx)
6. Restart DFRMM (f DFRMM,m=xx)
7. Be a good boy and delete the old journaldataset

For calulating the required size of your journal dataset you can use the formula from the Implementation and Custumization Guide:

• 1.5 KB for each user change made
• 1.5 KB for each data set retained by a vital record specification
• 1.5 KB for each data set no longer retained by a vital record specification
• 1.5 KB for each expiring volume
• 6.7 KB for each specific mount
• 8.3 KB for each scratch mount
• 1.5 KB for each volume retained by a vital record specification
• 2.6 KB for each volume in or out of the library
• 3.0 KB for each volume returned to scratch
• 3.5 KB for each volume moved to or from a storage location
• 1.5 KB for each volume that has not reached its expiration date and is no longer retained by a vital record specification
• 1.5 KB for each logical volume exported or imported
• 1.3 KB for each vital record specification created

My RoT when resizeing the journal dataset is to just triple the size, as changes regarding the tape environment are mostly not reflected in the sizing parameters of the journaldataset :)

To make this a complete HOWTO, below you will find the JCL to backup the journal when DFRMM is not active.... (dots inserted for readability)

//STEP EXEC.. PGM=EDGBKUP,
//............PARM='BACKUP(DSS)'
//SYSPRINT DD SYSOUT=*
//MASTER...DD DISP=SHR,DSN=YOUR.CDS
//JOURNAL..DD DISP=SHR,DSN=YOUR.OLD.JOURNAL
//JRNLBKUP.DD DSN=YOUR.JRNLBKUP
//............DISP=(,CATLG),
//............AVGREC=U,SPACE=(9000,(500,500)),
//............LRECL=9000,RECFM=VB