Limitations and restrictions for IBM i client partitions on systems managed by the Integrated Virtualization Manager

General notes

• IBM i client partitions do not own any physical I/O resources. All I/O resources on the IBM i client partition are virtual Ethernet and virtual storage (disk, optical, and tape).
• The IBM i client partition has no view of the physical hardware. This affects how certain commands can operate, the amount of data returned by existing CL commands, APIs, and MI instructions, and how you can perform some IBM i operations, such as servicing the partition.

Hardware and software prerequisites

For more information about the supported operating systems, see System software maps.

I/O, storage, and networking limitations

• You cannot assign any physical I/O resources to IBM i client partitions, including the following:
  • Host Ethernet Adapter
  • Host Connect adapter
  • Virtual OptiConnect
  • High-Speed link (HSL) OptiConnect
  Instead, the Integrated Virtualization Manager (IVM) management partition manages the physical I/O resources and provides virtual I/O resources to the client partitions.
• Virtual SCSI is the storage protocol available to IBM i client partitions.
• Virtual disk, virtual optical, and virtual tape are the storage devices available to IBM i client partitions. The virtual optical devices can map to physical DVD drives or to files.
• The IBM i client partition can have up to 32 virtual SCSI devices under a single virtual adapter. It can have up to 16 disk units (logical volumes, physical volumes, or files) and up to 16 optical units.
• The maximum virtual disk size is 2 TB. If you are limited to one adapter and you have a storage requirement of 32 TB, for example, you might need to make your virtual disks the maximum size of 2 TB. In general, consider spreading the storage over multiple virtual disks with smaller capacities. This practice can help improve concurrency.
• Mirroring is the redundancy option for IBM i client partitions. However, you can use multipathing and RAID on the Virtual I/O Server for redundancy.
• The communications protocol available to IBM i client partitions is virtual Ethernet.

SAS adapter performance considerations

If you are using the Virtual I/O Server with Peripheral Component Interconnect Express (PCIe) attached serial-attached SCSI (SAS) adapters to virtualize storage with the IBM i operating system, be aware of specific configuration options that maximize performance. Failure to implement these options can cause write performance degradation. Planning for these considerations ensures that the system is sized for the number of IBM i client logical partitions. For more information about how to configure your Virtual I/O Server, see the SAS Adapter Performance Boost with VIOS website.

Technologies that are not supported on IBM i client partitions

• High availability by using switched disk
• Virtual OptiConnect
• Cryptographic coprocessors
• IBM Facsimile for IBM i licensed program
• You can use the IBM Universal Manageability Enablement for IBM i licensed program on IBM i client partitions, with limitations.

Differences in IBM i operations

• Because the Integrated Virtualization Manager (IVM) management partition manages the physical hardware instead of IBM i, some APIs, machine instructions, and CL, dedicated service tools (DST), and system service tools (SST) commands are not available to IBM i client partitions. Also, the Disk Management graphical user interface enforces some restrictions.
• If you want to configure Electronic Customer Support (ECS) or Electronic Service Agent™ (ESA), use a virtual Ethernet connection such as Hypertext Transfer Protocol (HTTP). You cannot use a modem or dial-up connection.
• If you plan to use Operations Console to manage IBM i, consider the following points:
  • You must configure a local console on a network (LAN). You cannot configure a local console directly attached to the server (with or without remote access allowed) and you cannot configure a remote console through dial-up support.
  • You must configure virtual Ethernet bridging on the Integrated Virtualization Manager.
• You can perform main storage dumps in one of the following ways:
  1. You can write the data to virtual tape that is backed by a physical tape device.
  2. You can write the data to storage, copy it to virtual tape that is backed by files from the integrated file system, and then send it to IBM service and support by using FTP.
  3. You can write the data to virtual file-backed optical, transfer the data to physical tape, and then send the physical tape to IBM service and support.
• You can back up IBM i in one of the following ways:
  1. You can write the data to virtual tape that is backed by files from the IBM i integrated file system, and then send it to another system by using FTP.
  2. You can write the data to virtual tape that is backed by a physical tape device.
  3. You can write the data to a file-backed virtual optical device in the management partition, and then save the data to physical tape by using the backup command. For more information about the backup command, see Virtual I/O Server and Integrated Virtualization Manager commands. Backing up IBM i to optical devices (including file-backed optical devices) is typically slower than backing up IBM i to physical tape.
• Because the installation media for IBM i is greater than 2 GB, you must use the command line to upload the IBM i installation media to the management partition as follows:
  1. Open a virtual terminal session to the Virtual I/O Server command-line interface. For instructions, see Connecting to the Virtual I/O Server command-line interface.
  2. Run the following command:

     mkvopt -name MediaName -file FileName -ro

     Where:
     • MediaName is the name of the media that you plan to upload to the management partition. For example, v5r5m0drv250.002.
     • FileName is the name of the file that you plan to upload to the management partition. For example, v5r5m0-drv250.002.iso.
  3. Confirm that the media uploaded successfully by clicking the Optical / Tape tab in the View/Modify Virtual Storage window to view the media.