Enabling user mode access to the hardware accelerator

You can enable user mode access to the hardware accelerator by using the Hardware Management Console (HMC). The HMC must be at Version 9.1.940, or later.

About this task

The GNU zip (gzip) accelerators are compression and decompression cards that are used to increase server performance and network I/O efficiency. Quality of service (QoS) credits is a mechanism that is used to give logical partitions access to shared hardware accelerators. You can verify whether the server supports enabling user mode access to the hardware accelerator by using the lssyscfg command. To view the supported hardware accelerators types, along with the corresponding maximum Hardware Accelerator QoS, currently available Hardware Accelerator QoS, and pending available Hardware Accelerator QoS credits of the server, you can use the lshwres command. You can also use the lshwres command to view the amount of gzip QoS that is assigned to a logical partition. You can enable the gzip quality of service (QoS) credits for a logical partition that are either in the Activated or Not Activated states by using the chhwres command. With HMC version 10.1.1010, or later, you can enable the QoS credits for an IBM® i logical partition.

The logical partition is assigned credits only when the following conditions are met:
  • The server supports enabling the Hardware Accelerator.
  • The server supports the Hardware Accelerator type that you specify.
  • The operating system supports enabling QoS credits dynamically.
  • To assign QoS credit to an IBM i partition, the processor compatibility mode must be POWER10, or later. You can assign the gzip QoS credits to an IBM i partitions that are either in running state or inactive state.
  • Sufficient amount of Hardware Accelerator QoS credits are available that can be assigned to the logical partition.
To remote restart a logical partition that is enabled with gzip QoS credits, the destination server must support user mode access to the hardware accelerator. Additionally, the following conditions apply:
  • When the HMC that manages the destination server is at version 9.3.0, or earlier, the remote restart operation succeeds with the AIX®, and Linux® logical partition losing the gzip QoS credits after the remote restart operation completes.
  • The remote restart operation fails for an IBM i logical partition, if the destination HMC is at a version 9.2.950, or earlier.
  • The remote restart operation succeeds for a logical partition when there is a sufficient amount of available gzip QoS credits on the destination server. The logical partition is restarted with the same amount of gzip QoS credits that was available at the source server.
  • When the destination server has an insufficient amount of available gzip QoS credits, the remote restart operation succeeds and the logical partition is assigned partial gzip QoS credits that depends on the amount of available gzip QoS credits on the destination server.
  • When the destination server is a POWER9 processor-based servers and the HMC is at a version 10.1.1010, the remote restart operation for an IBM i logical partition can be successful . However, the IBM i logical partition is restarted with no gzip QoS credits.