i5/OS V6R1: It Must Be Getting Close, Since People Are Talking
January 28, 2008 Timothy Prickett Morgan
IBM‘s next generation of operating system for the System i platform, i5/OS V6R1, must be getting closer to its launch date. You can usually tell when an IBM operating system is getting close to launch because all at once, some people are aware of and talking about features in the future operating system that were not part of the official statements of direction and product previews we get from Big Blue.
Two weeks ago, the chatter started about a whole laundry list of features for i5/OS V6R1, and the noise is getting louder. The full details are obviously not available as yet, but there are a lot of enhancements, particularly in the area of virtualization, where the AS/400 and iSeries were leaders ahead of the Unix pack for many years (but considerably behind the mainframe). Now, the i5/OS platform is getting some Unix and Linux goodies.
Perhaps the most important virtualization enhancement I am hearing about is the support of the Virtual I/O Server, sometimes called VIOS, approach to I/O virtualization with i5/OS V6R1. Virtual I/O Server was created for AIX and Linux machines on the Power5+ generation of System p boxes. Now, Virtual I/O Server will apparently run on Power6-based servers with i5/OS V6R1. (Earlier iron and earlier i5/OS and OS/400 releases will not be supported, so I hear.) Virtual I/O server is part of the System p product line’s implementation of the Virtualization Engine hypervisor, which is called Advanced Power Virtualization. Virtual I/O Server is exactly what the name suggests. It is an I/O layer that allows multiple logical partitions–in this case on the System p boxes, running AIX or Linux–to share SCSI devices and Ethernet ports. With virtualized I/O, you do not have to have physical SCSI controllers and Ethernet adapters for each logical partition, which is expensive as well as wasteful and difficult to manage. Perhaps as important, by using Virtual I/O Server, companies can create logical partitions without having to resort to mucking about in the dreaded Hardware Management Console, or HMC. You use a program called the Integrated Virtualization Manager to create and destroy partitions instead.
The Virtual I/O Server apparently eats a partition on a machine, and then other partitions talk to it to get access to I/O. External DS4XX and DS8XX disk arrays can be the physical I/O behind the Virtual I/O Server, and presumably so can internal RAID 5 and JBOD disk arrays in the System i box running i5/OS V6R1.
You will recall, of course, that this Virtual I/O Server idea is just an interesting twist on how logical partitioning was originally set up on the AS/400s back in OS/400 V4. You had a primary OS/400 partition that acted as the host partition and managed all of the I/O, and then you had multiple quest OS/400 partitions that talked to the host partition to get access to disks and networks. (What is old is new again.) The difference this time is that a Virtual I/O Server is not an i5/OS, AIX, or Linux host partition that can do any useful work. It just does I/O for the other partitions on the machine, thank you very much. The question I have is does it create a single point of failure risk? What happens if that Virtual I/O Server partition goes down? Can you have two mirrored, fault tolerant partitions serving up I/O for the logical partitions next to it on the System i box?
IBM has apparently also figured out another way for i5/OS partitions to be spawned quickly and easily without resorting even to the Virtual I/O Server. A new feature called Virtual i5/OS partitions will allow one partition and its disk controllers and network adapters to share that I/O with another i5/OS partition. In this case, the idea is to be able to create development and test partitions quickly without having to buy redundant peripherals; once again, this new offshoot of logical partitioning requires i5/OS V6R1 and Power6 processors. So this is a new iron only proposition.
The software engineers putting together i5/OS V6R1 have also been hard at work weaving encryption into various layers of the system. There is also talk of some new disk clustering and data replication products, but it could turn out that these are just rebranded versions of the iCluster and Transformation Server products that IBM acquired when it bought Canadian HA software maker DataMirror last year.
The one thing that IBM has not given any hints on thus far is what i5/OS V6R1 will cost. And while I love technology and features as much as anyone in this world, the price is going to matter as much if Big Blue wants to get the base of vintage AS/400 and iSeries iron that is still largely running OS/400 to move forward. While the new nifty virtualization features rumored above are only available on Power6 iron–that means the System i 570 and the JS22 blade server is the only machinery where this stuff runs. (Older virtualization approaches requiring the HMC will still work on older iron and running i5/OS V6R1, of course.) With the user-priced System i 515 and 525 servers, the pricing is based essentially on seats and a nominal server fee–this is much easier to swallow than fees to get onto a Software Maintenance subscription plan. IBM should provide a very low-cost upgrade path for both hardware and software from customers with vintage boxes–perhaps scaled to what percent of their back-office workloads are on OS/400–to get loyal customers current in one giant wave. It can make more money further down the line, selling more processing and storage capacity and software to these customers once they get current. The other option is that many of these vintage shops will move to Windows and .NET, and IBM will get nadda.