POWER7 information

Limitations and restrictions for IBM i client logical partitions

With Virtual I/O Server, you can install IBM® i in a client logical partition on a POWER7® system. IBM i client logical partitions have unique system and storage requirements and considerations.

The following limitations and restrictions apply to IBM i client logical partitions of the Virtual I/O Server that are running on HMC-managed systems. IBM i client logical partitions that run on systems that are managed by the Integrated Virtualization Manager have additional limitations and restrictions. For details, see Limitations and restrictions for IBM i client partitions on systems managed by the Integrated Virtualization Manager.

Hardware and software prerequisites

  • The managed system must be one of the following servers:
    • 8202-E4B
    • 8202-E4C
    • 8202-E4D
    • 8205-E6B
    • 8205-E6C
    • 8205-E6D
    • 8231-E2B
    • 8231-E1C
    • 8231-E1D
    • 8231-E2C
    • 8231-E2D
    • 8233-E8B
    • 8248-L4T
    • 8268-E1D
    • 8408-E8D
    • 8412-EAD
    • 9109-RMD
    • 9117-MMB
    • 9117-MMC
    • 9117-MMD
    • 9119-FHB
    • 9179-MHB
    • 9179-MHD
    • 9179-MHC
  • The Virtual I/O Server must be at Version 2.1.2.11 or later.
  • IBM i must be at 6.1.1 or later.

I/O, storage, and networking limitations for virtual Small Computer Serial Interface (SCSI) adapters

  • The IBM i client logical 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 minus 512 bytes. If you are limited to 1 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. However, in general, consider spreading the storage over multiple virtual disks with smaller capacities. This can help improve concurrency.
  • Mirroring and multipath through up to 8 Virtual I/O Server partitions is the redundancy option for client logical partitions. However, you also can use multipathing and RAID on the Virtual I/O Server for redundancy.
  • It is required that you assign the tape device to its own Virtual I/O Server adapter, as tape devices often send large amounts of data, which might affect the performance of any other device on the adapter.

Virtual Fibre Channel limitations

  • The IBM i client partition supports up to 128 target port connections per virtual fibre channel adapter.
  • The IBM i client partition supports up to 64 SCSI devices per virtual Fibre Channel adapter. The 64 SCSI devices can be any combination of disk units or tape libraries. With tape libraries, each control path is counted as a unique SCSI device in addition to a single SCSI device per tape drive.
  • For IBM i client partitions, the LUNs of the physical storage connected with NPIV require a storage-specific device driver and do not use the generic virtual SCSI device driver.
  • The IBM i client partition supports up to eight multipath connections to a single fibre channel disk unit. Each multipath connection can be made with a virtual Fibre Channel adapter or with Fibre Channel I/O adapter hardware that is assigned to the IBM i partition.
  • Each virtual Fibre Channel adapter in an IBM i client partition must connect to a different physical Fibre Channel port. Connecting more than one virtual Fibre Channel adapter in the same client logical partition to a single physical Fibre Channel adapter port in the Virtual I/O Server is not supported.
Parent topic: Planning for the Virtual I/O Server

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Last updated: Thu, April 05, 2018