IBM i Storage Solutions

There are several considerations and components that make up a SAN solution with IBM i. These include selecting the right fibre channel adapter, SAN switches and also the version of the operating system to benefit from connectivity to IBM® TotalStorage® DS6000 and DS8000 series, IBM TotalStorage Enterprise Tape Libraries, and IBM TotalStorage Ultrium (LTO) Tape devices.

POWER6 and IBM i 6.1 (i5/OS V6R1) have made significant improvements in connectivity and performance of SAN attach subsystems.

The new Fibre Channel controllers 5749 (PCI-X) and 5774 (PCIe) have the following enhancements:

• Connectivity:
  • The controllers are Smart IOAs so an IOP is no longer required. This improves the number of ports per slot by 2X.
  • These controllers have 2 ports , a 2X improvement in number of ports per slot.
  • The number of LUNs (Logical Unit Number) supported for disk attach is 64, a 2X improvement in number of LUNs per port.
  • The combination of these improvement give a 4X improvement in number of ports per I/O slot and a 8X improvement in the number of LUNs per I/O slot. A LUN is how a single storage entity is defined on the SAN to the IBM i storage management (looks like a disk drive).

• Performance:
  • The new controllers have hardware enhancements that now execute operations previously done in software.
  • The removal of the requirement for the IOP reduces the overall overhead of the subsystem.
  • These enhancements enable SAN attached disk to approach integrated storage performance levels. Performance is very dependant on workloads and environments, work with your technical sales rep to understand how your environment will perform.

New capabilities:

• i 6.1, leveraging the capabilities of a Virtual I/O Server (VIOS), enables the attachment of the IBM System Storage DS4800 and DS4700 SAN storage devices. This provides another performance and price point for those considering SAN attached disk.
  • With i 6.1 IBM i can run as a client of another partition. VIOS runs in a separate AIX partition and is transparent to the Storage Manager in the IBM i client partition.
  • DS4700 and DS4800 attach through VIOS using AIX Fibre Channel adapters #5716, #5758, #5759, #5773 and #5774.
  • When purchasing DS4700 or DS4800 it is recommended that the user select the Fibre Channel disk drives option over the SATA disk drives, to optimize performance. If minimal cost is the main concern in the purchase decision, then SATA drives can be considered.
• The new Fibre channel controllers (#5749 and #5774) will allow IPL directly from SAN attached tape (alternate IPL)

The new Fibre Channel controllers can attach either Disk or Tape. There are two offerings available (POWER6 only):

1. #5749 PCI-X 4Gb (i 6.1 or above) Fibre Channel Adapter
2. #5774 PCIe 4Gb (i 6.1 or above) Fibre Channel Adapter

• Both Adapters Support the following Disk Device:
  • IBM Total Storage DS8000
• Both Adapters Support the following Tape Libraries on 2/2008:
  • IBM TotalStorage Enterprise Tape Drive TS1120
  • IBM TotalStorage TS3500 tape Library (no LTO 4 support)
  • IBM Enterprise Automated Tape Library 3494
• In 4Q 2008 the following support will be added to these adapters:
  • IBM TotalStorage TS3500 tape Library with LTO 4
  • IBM System Storage TS3100 and TS3200 with LTO 3 & 4
  • IBM System Storage TS 3310 with LTO 3 & 4
  • IBM System Storage TS3400 with 3592 E05

Pre POWER6 i 6.1 System i enables fibre channel connectivity through two separate fibre channel adapters.

1. #5704/#0625 PCI-X 2Gb (V5R2 or above) or #5761/#0629 PCI-X 4 Gb(V5R3 or above) Fibre Channel Tape Adapters for:

• IBM TotalStorage Enterprise Tape Drive TS1120
• 3580 IBM® TotalStorage® Ultrium (LTO)
• IBM Ultrium LTO Tape Subsystems (3582, 3583 and 3584)
• IBM TotalStorage TS3XXX Tape Library Family
• IBM TotalStorage TS3500 tape Library
• IBM Enterprise Automated Tape Library 3494

2. #2787 PCI-X 2Gb (V5R2 or above) or #5760 PCI-X 4Gb (V5R3 or above) Fibre Channel Disk Adapter for:

• ESS (2105)
• IBM TotalStorage DS6000
• IBM TotalStorage DS8000

When creating a Linux or AIX 5L partition on System i, you use the #0629 Fibre channel adapter for disk or tape.

Hardware and Software Requirements
I/O processor (#2844) dedicated for disk, or with up to two fibre channel tape adapters is required with OS/400 or IBM i environments pre POWER6 i 6.1. V5R3 is highly recommended for taking advantage of multipath I/O and improve overall resiliency. For boot from SAN capability use I/O Processor #2847.

Note: With Fibre Channel Adapter features #5704 or #5761, the fibre channel tape drives cannot be used as Alternate IPL (ALT-IPL) devices.

Direct Connection to Device:

• DS ports should be configured as Arbitrated Loop (FC-AL), except when using the I/O processor #2847 as a load source, then the connection should be Point to Point.
• IBM 3592 Model J1A or IBM 3590 (E/H models) and IBM LTO Ultrium 1 Tape devices can only be attached via Arbitrated Loop. IBM LTO Ultrium 2 Tape devices can be attached via Fabric or Arbitrated Loop in a SAN environment.

Connection through a SAN Network
IBM i supports a variety of Brocade, Cisco, CNT and McDATA SAN switches and directors. The latest support information can be located by selecting a particular SAN switch or director, and then looking at the in the switch interoperability matrix. The list of IBM supported SAN switches and directors can be found on the IBM TotalStorage Storage Area Network (SAN) Web site - http://www.ibm.com/servers/storage/san/index.html