Home > Storage > PowerMax and VMAX > Mainframe > Dell PowerMax: Data Protector for z Systems (zDP) Best Practices > zDP definition best practices
zDP can take snapsets with a five-minute granularity at minimum. You must evaluate your data-retention needs to preserve data if there is a logical corruption. These deployment practices are suggestions to provide direction and can help you consider the impacts of data retention and recoverability.
If your storage environment is sized correctly to maintain 240 snapsets, the following implementation provides granularity and increased security with your zDP snapsets.
Set your VDG to take a snapset every 12 minutes through the CYCLE_TIME that spans over 48 hours. This practice ensures that you have 240 snapsets before the oldest nonsecure, nonpersistent snapset is terminated.
Set the VDG definition so that the first Snapset at the top of the hour is secure.
Here is a sample VDG definition that may assist you with setting up your definition:
DEFINE VDG TESTVDG,
CYCLE_TIME(12,0,SECURE,1,4),
MAX_SNAPSETS(240),
SRP_TERM(80),
SRP_WARN(60),
TERMINATE_POLICY(OLDEST)
MODIFY VDG TESTVDG,ADD,
CCUU(770F,
7710,7711)
This definition does the following: