Parent topic: Planning for the operating system
Related information:
Virtual I/O Server software provides Virtual Small Computer System Interface (VSCSI) disk access, virtual Ethernet, and shared Ethernet adapter capability to client logical partitions within the system, allowing the client operating systems to share SCSI devices and Ethernet adapters.
The Virtual I/O Server server partition owns physically attached SCSI I/O devices. The Virtual I/O Server exports one or more of these devices to client logical partitions as Virtual SCSI resources. The POWER Hypervisor™ (PHYP) connects the server VSCSI adapters to client logical partitions. VSCSI server and client adapter drivers use the POWER Hypervisor to communicate control data.
The Direct Memory Access (DMA) controller on the physical adapter card uses redirected SCSI Remote Direct Memory Access (RDMA) Protocol to transfer stored data to and from client buffers. Virtual I/O Server securely targets memory pages on a client to support the client virtual SCSI.
The Virtual I/O Server supports logical mirroring and RAID configurations. Logical volumes created on RAID or Just a Bunch of Disk (JBOD) configurations are bootable. The number of logical volumes is limited to the amount of storage available and by architectural limits.
Virtual SCSI is based on a client-server relationship, which requires some capacity planning for additional latency, bandwidth constraints, and shared Ethernet activity. For more information about planning, deploying, and managing virtual SCSI, see the Configuring section of the PowerVM Information Roadmap.
