Virtual SCSI adapters

Virtual SCSI (Small Computer Systems Interface) adapters provide one logical partition with the ability to use storage I/O (disk, CD, and tape) that is owned by another logical partition.

A virtual SCSI client adapter in one logical partition can communicate with a virtual SCSI server adapter in another logical partition. The virtual SCSI client adapter allows a logical partition to access a storage device being made available by the other logical partition. The logical partition owning the hardware is the server logical partition, and the logical partition that uses the virtualized hardware is the client logical partition. With this arrangement, the system can have many server logical partitions.

For example, logical partition A provides disk space to logical partitions B, C, and D. A logical partition can simultaneously use virtual I/O from more than one logical partition. Therefore, using the example, while logical partition A provides disk space to logical partitions B, C, and D, logical partitions A and B can use a tape drive connected to logical partition D. In this case, A is serving D for disk space, while D is serving A for the tape device.

Virtual SCSI allows you to simplify the backup and maintenance operations on your managed system. When you back up the data on the server logical partition, you also back up the data on each client logical partition.

Virtual SCSI server adapters can be created only in logical partitions of type IBM® i and Virtual I/O Server.

The virtual SCSI client device driver is not capable of storage protection using Redundant Arrays of Independent Disks (RAID). While the Linux® operating system allows software RAID protection of virtual disks, the recommended technique for protecting disk storage is to configure the virtual I/O storage server to perform the disk protection.

For HMC-managed systems, virtual SCSI adapters are created and assigned to logical partitions using partition profiles.