It used to be that every partition running on IBM i required hardware such as disk storage and network connections dedicated to that partition, which is inflexible and can be costly because of the hardware that is required for each partition.
In response, IBM developed the Virtual I/O Server (VIOS), which addresses these issues by acting as a host partition for I/O. VIOS is a logical partition (LPAR) that has physical I/O such as disk storage and network adapters connected to it. This I/O is then provided to LPARs running IBM i (or AIX or Linux) within the same server.
Quick and easy to deploy, the pre-defined VIOS monitoring template comes ready to provide automation and alerts around hardware and software errors, inform you of changes to key files within the VIOS, alert you to sustained use of CPU within this environment, and monitor file system, disk space, and memory usage on the VIOS partition.
There are several benefits to using VIOS instead of connecting the I/O directly to an IBM i LPAR. For example, you can reduce the number of physical I/O adapters, saving both cost and the number of adapter slots needed—an important consideration with today’s limited adapter support.
VIOS also allows you to run IBM i on a blade as opposed to the traditional integrated hardware systems. You can consolidate Intel blades (running Windows or Linux) and Power Blades (running IBM i, AIX, or Linux) within a single BladeCenter.
For those using storage area networks (SANs) such as IBM’s DS3000 or DS4000 families for consolidating storage for Intel servers, these SANs attach to a VIOS partition rather than directly to IBM i and can be used by that route.
Ultimately, you gain greater flexibility by sharing I/O resources between partitions and by being able to create new LPARs—no new physical hardware required. VIOS greatly improves the way multiple partitions can be supported on a single system and helps to keep costs down, which is always nice.