Hardware Today: Understanding IPMI
One of the most important pieces of news to come out of last week's Intel Developers' Forum was the release of the Intelligent Platform Management Interface (IPMI) version 2.0.Intel last week unveiled version 2.0 of its Intelligent Platform Management Interface (IPMI) specification, which provides a standardized way for enterprises to monitor the mechanical elements of a computing device's operation. Carl Weinschenk explains the basics of IPMI and describes what's new in 2.0.
Although IPMI is far from sexy -- it deals with things such as whether fans are turning and voltage flowing -- and easily gets obscured by other advances, it is becoming an important part of server management.
IPMI 2.0 is the third iteration of the specification set. Although it is not an official specification (in the sense of having gone through the IEEE or IETF), it offers all participating vendors -- and there are plenty of them -- a standardized way to monitor the mechanical elements of a computing device's operation. In addition to the fans and voltage, IPMI keeps tabs on temperature and power supply status. And that's not all it can do: The latter two versions of IPMI can reboot machines remotely.
Before IPMI, each computer vendor developed its own way to monitor the performance of the various pieces of its platform. This tended to marry an enterprise or telecommunications company to a specific vendor and generally was an inefficient way of managing them. The chronic weakness has grown more significant as computing devices in data centers and telecommunications networks proliferate.
Intel doesn't play favorites among the hardware vendors, so it made sense for the company to develop and promote a process that rationalizes the landscape. Other initial backers were Hewlett-Packard, Dell, and NEC. "The promoters' intention was to come up with a standard way of getting information across different platforms," says Dave McKinley, vice president and CTO of Augmentix, a server vendor based in Sugar Land, Texas.
According to a report by the Aberdeen Group, IPMI is currently in use by more than 150 vendors. The Aberdeen Group offers an impressive list of related benefits that the basic technology delivers. Some of these advantages are true of any strong diagnostic package. Others, however, can be realized only by a multivendor standard. The latter advantages include lowering the cost of ownership by rationalizing operational support and standardizing across a number of hardware and software products and platforms.
That's all fine and good, but how exactly does IPMI work? McKinley explained that a small, separate processor, called a baseboard management controller (BMC), sits on the motherboard. The BMC links to the main processor and various on-board elements. It monitors, and to some degree manages, the health of the various physical elements. Since there is a separate processor, the system works regardless of whether the main processor is operational. In IPMI 1.0 (released in 2001), the connection was through the serial port. The two subsequent versions of the standard deepened its monitoring capabilities and enabled it to function remotely.
IPMI's remote element was key to many. "From the IT perspective [the main difference is] is being able to gain access to the server over the LAN," says Steve Rokov, director of marketing for OSA Technologies. IPMI 1.5 does this and offers remote management capabilities for rebooting, resetting, and recycling power, McKinley says.
Clearly, security is a key element of any plan to enable remote control of network elements. The version released last week -- Intel tends to update IPMI at its developers' conference -- focuses on this issue. IPMI 2.0 supports advanced authentication through a technique called Secure Hash Algorithm-1 (SHA-1). Advanced encryption is provided by the Advanced Encryption Standard (AES).
IPMI 2.0, which is backward compatible with version 1.5, also supports virtual LANs. VLANs play into the effort to heighten security by giving administrators more control over who gets access to the machines. "You now have the concept of a management LAN on a physical LAN," Rokov says. "You can now protect the data on the LAN from the other traffic. An alert can go out on the VLAN that only certain consoles can see and initiate commands."
IPMI is a family of specifications with which IT managers and their staffs should make themselves familiar. From a high level, it is another tool for managing the complexity of modern data centers and field operations. It does this in several ways: It complements the operational support systems with which it shares information. It also provides some of the same remote operational functions provided by keyboard, video and mouse (KVM) technology. Finally, IPMI can help IT managers efficiently manage grids, clusters, virtualized machines, and other emerging strategies for grouping PCs and servers.
Rokov expects IPMI 2.0 will be discussed by the parties involved for the next few months, and it will become "official" some time next year.
Carl Weinschenk writes a weekly server hardware series for ServerWatch.