Through “Work with Migration Control Groups” (WRKCTLGBRM *MGR), this new support allows you to enter new “Item Type” values of *LNK and *OBJ.
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New control group attributes for *SSD to move to preferred SDD storage, and *NONSSD to move back to HDD storage, were added, along with a new *RDRATIO as a new migration rule criteria.
Here is an example of migration control group attributes being set using the new *SSD and *RDRATIO attributes:
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The migration rule checking for *OBJ Item Types is applied to the individual objects in the object list, but the migration is for the entire object list. In the example above, if one of the objects in the object list has a read-to-write ratio greater than 80, then all of the objects in the list are migrated, not just the single object which met the criteria.
These new attributes are allowed only for *OBJ Item Type and allow a user to specify the ratio of reads to writes for the DB files in the object list as migration criteria. BRMS uses “Change Physical File” (CHGPF) and “Change Logical File” (CHGLF) commands under the covers to implement the SSD functionality. One of the main criteria for utilizing SSD is this ratio of reads to writes. More information on this database function can be found in the following White Paper and Article:
White Paper: Customer Use of SSD (Solid State Drives)
Article: Moving Data to Solid State Drives