|Sorting out the features|
|With so many HBA features, knowing which ones matter and which ones don't|
| can be a challenge for just about any administrator. Here's a short description of some of the features shipping today that may influence your buying decision.
DATA BUFFERS. Data buffers serve as a necessary and valuable component of Fibre Channel (FC) HBAs, but they shouldn't be thought of as a differentiator when selecting an HBA. This feature primarily becomes important in long-distance SANs, as higher buffer credits are needed to accommodate the longer latency periods when the data is sent and received.
FC SPEED. Two-gigabit FC HBAs are now available from every HBA vendor and make up the majority of HBA sales. They still autosense down to 1Gb to work with existing environments. The road map for next-generation HBAs is still uncertain, but 4Gb appears likely because, unlike 10Gb FC, it is backward-compatible with 1Gb and 2Gb FC, and will cost about the same as the 2Gb cards shipping today.
WWN SPOOFING. World wide name (WWN) spoofing is an interesting feature, but it has only limited application in today's SAN environment. Most HBA vendors offer it for customers who request it. Vendors see this feature primarily used in clustered server environments and feel the increased security risks outweigh the potential benefits of this technology.
CONTEXT SWITCHING. Context switching also serves as a necessary and valuable component of FC HBAs, but again, it shouldn't be thought of as a differentiator when selecting an HBA. This feature primarily takes on importance when the speed in routing a FC packet is a factor and SANs are already running at high capacity.
LOAD BALANCING/MULTIPATHING. These interrelated features serve as a requirement for any highly available server. Load balancing will balance the FC traffic over two or more paths through the SAN, while the multipathing feature enables the operating system to have more than one path to disk, should one HBA fail or a path through the SAN becomes unavailable.
CIM COMPLIANCE. Charles Kraus, HBA business unit director of Milpitas, CA-based LSI Logic, sees CIM functionality as one of the critical new features all HBA vendors must now offer. This feature will permit the management of heterogeneous SANs and enable certain functions (such as performance monitoring, remote firmware and driver upgrades and troubleshooting) across all HBAs, regardless of vendor.
Installing an HBA
Setting up any HBA requires answering various questions: What operating systems will it work with? What settings and configuration files need tweaking prior to, during and after installation? How does the HBA discover new LUNs on the SAN?
Probably the biggest initial task facing many system administrators centers on the installation and configuration of a new HBA in a server. Loading the correct driver, verifying the firmware, tweaking the configuration files, ensuring it is compatible with your SAN and discovering the LUNs for the first time can take hours--if not days--for new or experienced SAN administrators.
HBA vendors now ship HBAs that address many of the issues surrounding the initial install and configuration by eliminating or automating these tasks. Most vendors--including Atto Technology, Emulex, QLogic, and LSI Logic--now offer HBAs for Windows systems that are plug-and-play and require little or no intervention on the part of the system administrator to install and configure.
Amherst, NY-based Atto Technology's product manager, Pete Donnelly, lists interoperability of Atto's HBAs with Microsoft Windows as a top priority. Atto is currently working with Microsoft to ensure its HBAs are automatically recognized by Windows after being installed.
For Unix environments, installations are far from being hassle free, but there's encouraging work in this area. According to Charles Kraus, HBA business unit director of LSI Logic, Milpitas, CA, LSI Logic prepared a driver that will work under Linux and released that driver code to IBM and Hewlett-Packard, who then modified the driver for their specific versions of Unix (AIX and HP-UX). Kraus says none of the other HBA vendors offer native AIX or HP-UX drivers.
Sun Microsystems appears to be heading down the same path as HP and IBM. While all of the major HBA vendors currently provide drivers for Sun Solaris, Sun has included the leadville driver as part of its current SAN Foundation software. This driver offers full fabric support, along with failover and management capabilities, and replaces the one provided by the HBA vendors, though this driver currently only works with the newest HBAs provided by QLogic. The upside of this approach, according to Christopher Poelker, a storage architect with Hitachi Data Systems (HDS), is that the leadville driver removes the need to edit the sd.conf file because it runs at the kernel level and uses a different configuration file--sdd.conf--which needs no editing.
Managing an HBA
Once an HBA is installed, the focus changes to managing it. Here's where new struggles arise. In some large IT departments when upgrades occur on the SAN, administrators can find themselves at their wit's end trying to figure out which server has what HBA with what firmware and driver level.
Again, new features and tools from vendors such as Emulex, JNI and QLogic enable administrators to better control this part of their environment.
Costa Mesa, CA-based Emulex offers a central management console called HBAnyware that performs three critical management tasks that work in conjunction with their native driver kit.
HBAnyware grants administrators the ability to do local and remote discovery of Emulex HBAs. It also contains the ability to do local and remote management and real-time installation of firmware anywhere in a Fibre Channel (FC) SAN. Finally, it allows the administrator to gather FC HBA port status, attributes and statistics.
While having software like this becomes a powerful tool for administrators, knowing how to use it becomes just as critical. For instance, HBAnyware grants administrators the ability to upgrade Emulex HBA firmwares and drivers remotely. What the administrator needs to know is that upgrading Emulex's firmware can be done nondisruptively and won't require a reboot; however, changing its driver can be disruptive and may require a server reboot. So, administrators need to practice a think-first, act-second mentality when performing tasks like this.
The rest of the HBA vendors primarily provide tools that are locally installed and managed on each server. Atto has its ExpressPCI Configuration Tool for driver and firmware upgrades for its HBAs. Atto Technology's Donnelly says that while its firmware and driver updates may be done on the fly, he doesn't recommend that approach--especially for novice users. He sees the management of these functions being done locally for the time being, though when CIM becomes universally available, there will be more opportunities to perform these tasks remotely.
JNI and LSI Logic also provide similar utilities that simplify HBA installation and configuration for their specific HBA cards, though the other major vendors lack the central management control consoles offered by Emulex. LSI Logic's Charles Kraus says that interoperability with third-party SAN management software tools such as EMC's ControlCenter is one of LSI Logic's priorities for 2003. LSI Logic also plans to have a tool similar to Emulex's HBAnyware released by the end of 2003 to centrally manage LSI Logic HBAs.
QLogic provides a management tool similar to HBAnyware called SANblade Manager, which simplifies the configuration and setup of QLogic HBAs. This tool works in conjunction with its SANblade Control FX utility, which is controlled by the SANblade Manager software. The SANblade Control FX utility enables a faster HBA installation and configuration through a wizard-like interface, includes diagnostic tools that report on the firmware and driver levels and also includes a display that shows attached devices and LUN properties.
This was first published in July 2003