// Module included in the following assemblies:
//
// * scalability_and_performance/ibm-z-recommended-host-practices.adoc

:_mod-docs-content-type: CONCEPT
[id="avoid-virtual-scsi-devices_{context}"]
= Avoid virtual SCSI devices

[role="_abstract"]
Configure virtual SCSI devices only if you need to address the device through SCSI-specific interfaces. Configure disk space as virtual block devices rather than virtual SCSI devices, regardless of the backing on the host.

However, you might need SCSI-specific interfaces for:

* A logical unit number (LUN) for a SCSI-attached tape drive on the host.

* A DVD ISO file on the host file system that is mounted on a virtual DVD drive.
