What is Vios?

What is Vios? 

 The virtual i/o server is an appliance that provides virtual storage and shared ethernet adapter capability to client logical partitions.it allow a physical adapter with attached disks on the virtual i/o sever partition to be shared by one or more partitions,enbling clients to consolidate and potentially minimize the number of physical adapters required.

VIOS is a special purpose partition that can serve I/O resources to other partitions. The type of LPAR is set at creation. The VIOS LPAR type allows for the creation of virtual server adapters, where a regular AIX/Linux LPAR does not.

• VIOS works by owning a physical resource and mapping that physical resource to virtual resources. Client LPARs can connect to the physical resource via these mappings.

• VIOS is not a hypervisor, nor is it required for sub-CPU virtualization. VIOS can be used to manage other partitions in some situations when a HMC is not used. This is called IVM (Integrated Virtualization Manager).

Depending on configurations, VIOS may or may not be a single point of failure. When client partitions access I/O via a single path that is delivered via in a single VIOS, then that VIOS represents a potential single point of failure for that client partition.

• VIOS is typically configured in pairs along with various multipathing / failover methods in the client for virtual resources to prevent the VIOS from becoming a single point of failure.

• Active memory sharing and partition mobility require a VIOS partition. The VIOS partition acts as the controlling device for backing store for active memory sharing. All I/O to a partition capable of partition mobility must be handled by VIOS as well as the process of shipping memory between physical systems.