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Guest virtual SCSI adapter selection
19 Dell EMC SC Series: Best Practices with VMware vSphere | 2060-M-BP-V
5 Guest virtual SCSI adapter selection
When creating a new virtual machine, there are four types of virtual SCSI (vSCSI) controllers to choose from.
Based on the operating system selected, vSphere will automatically recommend and select a SCSI controller
that is best suited for that particular operating system. The best practice is to follow the client
recommendation. The nuances of each adapter are described in the following subsections.
vSCSI adapter selection
5.1 BusLogic Parallel
This vSCSI controller is used for older operating systems. Due to the queue depth limitations of this controller,
it is not recommended unless it is the only option available for that particular operating system. Certain
versions of Windows issue only enough I/O to fill a queue depth of one.
5.2 LSI Logic Parallel
Because many operating systems support this vSCSI adapter, it is recommended for virtual machines that do
not support the LSI Logic SAS adapter.
5.3 LSI Logic SAS
This vSCSI controller is available for virtual machines with hardware versions 7 and later. It also has similar
performance characteristics of the LSI Logic Parallel. This adapter adds support for SCSI-3 reservations,
which are required for Microsoft Cluster Services (MSCS). Some operating system vendors are gradually
withdrawing support for SCSI in favor of SAS, making the LSI Logic SAS controller a good choice for future
compatibility.
5.4 VMware Paravirtual
This vSCSI controller is a high-performance adapter that can result in greater throughput and lower CPU
utilization. More information about the usage and limitations of this adapter can be found in the section, About
VMware Paravirtual SCSI Controllers, in the vSphere Virtual Machine Administration Guide in the VMware
vSphere documentation.