Systems Software Stack Tweaked For Power Systems
October 14, 2019 Timothy Prickett Morgan
As part of the October Power Systems announcements, IBM has made some minor tweaks to the systems software stack that runs underneath IBM i, AIX, and Linux on its Power-based systems.
In announcement letter 219-451, IBM reveals enhancements to its PowerVM server virtualization hypervisor, the PowerVC implementation of the OpenStack cloud controller (which presumably has a pretty short life now that IBM owns Red Hat), and its Virtual HMC (vHMC) hardware management console for Power iron.
The details are a bit thin, but IBM has made improvements with PowerVM V3.1.1 so Live Partition Mobility live migration of logical partitions – what everyone else calls a virtual machine – has better performance. The exact nature of that performance improvement is not clear as we go to press. IBM is also supporting DRAM-based persistent memory – which does not mean Intel’s Optane persistent memory but rather NVDIMMs which mix flash and DRAM – so VMs can be stored persistently on that memory and therefore system restarts and VM reloads can happen a lot quicker. IBM has also enhanced virtual network interface card (vNIC) and related Single Root Input/Output Virtualization (SR-IOV). Here are the tweaks IBM has made on the I/O front with PowerVM V3.1.1
- An increased number of NPIVs allowed per Fibre Channel port on the 32 GB Fibre Channel HBA. The current limit is 64, and more NPIVs per port will provide better utilization, density, and efficiency.
- NPIV multiqueue (VIOS server) for improved performance and scalability.
- Fibre Channel device labels for improved manageability.
- iSCSI performance enhancements.
- Improved VIOS Upgrade Tool capabilities.
- SSP network resiliency improvements.
PowerVM V3.1.1 runs on Power7+, Power8, Power8’, Power9, and presumably the forthcoming Power9’ systems, the latter of which are due in early 2020. PowerVM comes in a low-cost Linux Edition, plus a Standard Edition and an Enterprise Edition that adds in support for IBM i and AIX guest operating systems. The updated PowerVM will be available on November 15.
The new virtual HMC, which is at V9.1.940 and which is being launched concurrently with the Power Systems firmware FW940 update, is available running on Linux instances on either X86 or Power iron, will be available on November 22. It has the following enhancements:
- User mode NX accelerator enablement
- Support for SR-IOV logical ports in IBM i restricted I/O mode
- Injection of IBM i license keys
- Improved LPM error messages
- Ability to manage resource roles automatically in HMC
- Progress indicators for specific HMC commands
- Email notifications for scheduled operations
- IBM PowerSC Multi-Factor Authentication (MFA) in-band support for HMC
The techies we have talked to are excited about the ability to inject IBM i license keys into the HMC. As far as we know, the GZIP NX accelerator that has been enabled for the vHMC running atop Linux is still not available to run natively with IBM i. It might be useful to zip data at line speed inside the Power9 processor for IBM i workloads. But no one is talking about this.
The PowerVC variant of OpenStack, which is now coming out with V1.4.4. is probably not used by very many IBM i shops unless they have AIX or Linux as an anchor and happen to also have some IBM i instances. Here are the updates here:
- IBM i license key injection
- Hitachi GAD support
- Initiator storage tagging
- Live Partition Mobility VMs to the original system after evacuation
- Ability to pin VMs to a specific host
- Ability to dynamically add PowerVC created VM to an HMC user resource role
- Inactive partition migration
- Image sharing between projects
- New restricted administrator assistance role, with no deletion access
- NovaLink support for multivolume attachment
- FlexVolume driver support for Red Hat OpenShift
We still don’t know what IBM plans to do consolidate, refactor, or resolve the dual lines of OpenStack on its Power Systems iron now that it owns Red Hat and has its OpenStack distribution under its control as well as the PowerVC Power Systems variant. For the moment, these two products are separate, and it could take years for Power iron to shed its homegrown OpenStack VM and Kubernetes container environments and just tightly integrate AIX and Linux and possibly IBM i with the Red Hat code. It would be interesting to see how IBM might make more use of the KVM hypervisor, too, including a port of IBM i and AIX. So far, mum’s the word out of Big Blue on all of this.