Home > Storage > PowerMax and VMAX > Mainframe > Dell PowerMax: Data Protector for z Systems (zDP) Essentials > Starting zDP through mainframe enablers
After users have added and customized the configuration parameters for zDP, zDP should be started from the EMCSCF started task. Use the command “F emcscf,zDP START vdg_name”. If the VDG_NAME is found within SCF, the zDP started task creates SNAPSETs in that VDG. There does not need to be a “Target Set” for the SNAPSET to be created. This is based on the ‘target-less snapshot’ principal underlying SnapVX.
When users start the VDG, the z/OS SYSLOG SCF and EIP messages indicates that the SNAPSET has been created. For example, the VDG called VDGNEW and zDP produced the following messages in SYSLOG. (Also, users can reference a LOGOPT DD statement to see zDP messages.
Snapshot creation message:
SCF0740I ZDP START TESTVDG1
SCF0741I ZDP START command accepted
SCF0746I ZDP VDG TESTVDG1 Started
EIP0200I *** EMC zDP – V10.0.0 (000) - Tuesday, July 19, 2022 ***
EIP0250I VDG TESTVDG1, SMF Recording enabled, Record Id 228, Tracks
EIP0201I VDG TESTVDG1, Beginning cycle 39, Snapset TESTVDG1.......170
951304C00039
EIP0217I VDG TESTVDG1, Devices validated for consistency, via ECA
EIP0204I VDG TESTVDG1, SNAPSET TESTVDG1.......170951304C00039 created
EIP0202I VDG TESTVDG1, Completed cycle 39, next cycle scheduled for
13:14:32
When a zDP creates snapsets, it refers to the duration and frequency of the snapset as a cycle. For example, the VDG ‘CYCLE_TIME(10,35)’ parameter, indicates to zDP to take a snapset of every volume in this VDG every 10 minutes and stop the VDG from taking any more snapsets after 35 cycles. Users can see the first cycle in Figure 3. This is an important concept to understand because when users query the VDG after it has taken 35 cycles, a unique ‘SNAPSET_NAME’ exist in the output. Each ‘SNAPSET_NAME’ represents one cycle.
To find out the names of the SNAPSETs for a specific VDG, use the QUERY command. When a VDG takes a SNAPSET, it uses the Enginuity Consistency Assist feature of PowerMaxOS to ensure that the snapset dependent write is consistent.