Allow your server to change as your business changes.
IBM i has a long history of virtualization. If you haven't looked into virtualization since IBM i 6.1, there are some key enhancements you should know about.
LPARs and Virtual Storage Serving
If you're interested in trying out any of the new features that IBM i 7.1 may offer but don't have the extra I/O slots required to create a new LPAR, you may want to consider using the virtual storage serving capability that is built into your current IBM i 6.1 (or 6.1.1) LPAR. An IBM i 6.1 LPAR or later can virtualize disk and optical devices to other 6.1, 6.1.1, and 7.1 LPARs. By using Virtual Ethernet with some networking functions—such as proxy ARP, Network Address Translation, or TCP/IP routing—you can replace a physical Ethernet adapter in the client partition.
If your LPAR I/O requirements include only disk, optical, and Ethernet, you can create an entire 7.1 LPAR without any new hardware, but if your hardware requirements are more complex, you can use a combination of virtual and physical hardware resources. For example, you can have a WAN adapter for fax support or a storage adapter to get access to a tape device but still get some or all your disk from another LPAR that has excess disk capacity.
Another good use case for the IBM i virtual storage server is if you find an I/O feature that IBM i 7.1 supports that you want to use, but you're not ready to move your applications to IBM i 7.1. You can create an IBM i 7.1 LPAR that will make use of the new I/O feature but still give storage and Ethernet to client LPARs that could remain at IBM i 6.1.
Virtual Optical Devices
Using a virtual optical device is a great way to install new IBM i 7.1 partitions or even your IBM i 6.1/6.1.1 partitions. Virtual optical devices can be backed by physical optical devices, image catalog optical devices, or NFS optical devices. If you're doing multiple installs at the same time, you may want to investigate using dependent image catalogs. This allows for a single set of optical images to be referenced independently by multiple partitions. For configurations where the optical device is not capable of dynamic LPAR (DLPAR), such as systems that have optical devices in the CEC frame, virtual optical clients are the only way to share that device and may negate the need for an additional optical drive to install LPARs.
Internet SCSI (iSCSI)
The IBM i virtual storage server can provide storage to x86 Internet SCSI (iSCSI) clients. In IBM i 7.1, there is new support for using a standard network adapter as an iSCSI software target Host Bus Adapter (HBA). This will allow customers to use a broader range of adapter technologies for their iSCSI solution, such as 10 Gbit and PCIe.
Virtual I/O Server (VIOS)
While the IBM i virtual storage server functionality is a great way to be flexible in your I/O usage, another powerful way to take advantage of excess I/O capacity is to use the Virtual I/O Server (VIOS). IBM i's support for the VIOS was first available in IBM i 6.1 and has had many enhancements since then. Among those enhancements are virtual SCSI tape, Active Memory Sharing, N Port ID Virtualization (NPIV), SSD recognition, end-to-end virtual device mapping, VSCSI Client Multipath support, and additional VSCSI external storage support.
If you are a SAN storage user, one of the most exciting new technologies is NPIV. This technology allows a single port on a fibre channel HBA to be shared by up to 64 LPARs. If you happen to have many smaller LPARs that currently don't utilize the bandwidth of an entire HBA, you can significantly reduce the number of HBAs, cables, and switch ports required.
With the use of NPIV comes the full support for PowerHA SystemMirror, which includes the new IBM i 7.1 support for LUN-level switching. High availability (HA) configurations that use IASPs are very good candidates to take advantage of NPIV. At a minimum, an HA partition is required to have four separate fibre channel HBAs. For redundancy, there are two HBAs for SYSBASE and two HBAs for each IASP. Even if the HBA has two ports, you are still required to have four HBAs because the IASP switch requires an adapter reset to do the switch. In an NPIV configuration, each HBA port is virtualized as a virtual fibre channel (VFC) adapter. You can now utilize all four ports on two dual-port HBAs because the adapter reset is now on the VFC adapter only and will not affect anyone else on the physical port or HBA.
NPIV also enables dynamic redistribution of ports to different LPARs without SAN reconfiguration. Each client LPAR VFC adapter is assigned a unique Worldwide Port Name (WWPN), which is used to associate SAN device ports with the client adapter. The client VFC adapter is paired with a server VFC adapter in the VIOS, which in turn is associated with a physical HBA port. The physical-port-to-VFC-adapter mapping can be dynamically changed with the client seeing little to no interruption. This may be useful when migrating from one HBA to another to do concurrent maintenance. It is also useful for rebalancing physical port utilization if one HBA becomes more heavily utilized.
At the time of this writing, within the last year, IBM has added support for several devices when attached with NPIV. For disk storage, IBM supports the DS8100, DS8300, and DS8700. For tape libraries and devices, IBM supports the following:
- 3573 (TS3100/TS3200) with LTO3 and LTO4 tape drives
- 3576 (TS3310) with LTO3 and LTO4 tape drives
- 3577 (TS3400) with TS1120 and TS1130 tape drives
- 3584 (TS3500) with LTO3, LTO4, TS1120, TS1130, and 3592-J1A
For VSCSI attached devices, IBM has also added within the last year to what it supports as a client of the VIOS. For disk, new support includes DS8700, XIV, SVC, DS5020, DS5100, DS5300, and DS3950. For VSCSI tape devices, new support includes TS2240, LT04, DAT72, DAT160, and DAT320.
Multipath I/O (MPIO)
In IBM i 6.1, the only way to have virtual disk redundancy through two VIOS LPARs is to use mirroring at the IBM i client level. IBM i 6.1.1 introduced IBM i client Multipath I/O (MPIO) through up to eight VIOS LPARs. This allows for the flexibility to maintain availability while doing maintenance on a VIOS LPAR and in some configurations can significantly reduce the disk capacity required.
Hardware Management Console (HMC)
The Hardware Management Console (HMC) has also added many improvements to the management of VIOS virtual I/O. You can now manage your VSCSI storage, NPIV adapters, and Shared Ethernet Adapter (SEA) network configuration through the HMC GUI. The HMC also provides the ability to view the mapping of a virtual device in a client partition to the physical device in the VIOS. The command-line interface for this function is useful for documenting your current settings in case of later changes.
Virtualization is a useful tool to allow your server to change as your business changes.
As the demands of IT increase, the IBM i platform continues to provide the flexibility to get the most out of your server.