Performance Considerations
As customers begin to deploy z/VM 7.3 they might wish to give consideration to the following items.
4 TB Exploitation
With 4 TB Exploitation clients can now configure their LPARs to have 4 TB of central storage. This gives clients room for workload growth.
The 4 TB function has been available for z/VM 7.2 since 1Q21 but some customers might not have the PTF or might be unfamiliar. For more information refer to our article, linked above.
Dynamic Memory Downgrade
With Dynamic Memory Downgrade (DMD) clients can now configure their memory so that some of it can be removed. This gives clients the ability to move memory among LPARs as is needed for load balancing.
The DMD function has been available for z/VM 7.2 since 2Q21 but some customers might not have the PTF or might be unfamiliar. For more information refer to our article, linked above.
NVMe EDEVs
With NVMe EDEVs LinuxONE clients now have inexpensive, fast, removable disk storage at their disposal. Some interesting use cases come to mind:
- Paging space. Set up EDEVs with PAGE extents and then page to them just as one would page to ECKD or to FCP EDEVs.
- Storage for data that needs to be put under lock and key. Set up EDEVs with PERM extents, put user minidisks on them, copy the data to those minidisks, then go unplug the SSD and lock it up.
- Storage for data that needs to be sent somewhere. Remove as described above, then ship the SSD to where it needs to go.
Creative minds will no doubt think of other uses.