SCSI contrller的几种类型的区别

在VMware vSphere Web Client中, 可以为虚拟机添加一个新的SCSI controller, 选项中包含如下的类型, 那么他们有什么区别呢? 如何选择呢?

BusLogic Parallel

VMware平台上最早的vSCSI controller之一. 最早版本的Windows默认就有它的驱动, 使得安装特定版本windows时会比较容易. 性能跟LSI Logic驱动没法比, 因为Windows驱动中的Queue Depth被限制为了1, 所以一般都会加载LSI Logic驱动作为替代. 虽然还在, 还可用(Windows 2000), 但是可以被认为是老古董了.

LSI Logic Parallel

这是VMware平台上的另一个最早的vSCSI controller了. 大多数操作系统都有支持32的queue depth的驱动. 这是一个非常平常的选择, 但还不是默认选项.

LSI Logic SAS

这是一个支持面向未来的标准的一个并行驱动的进化版本. 微软要求Windows 2008或更新的版本中的MCSC必须使用LSI Logic SAS.

VMware Parevirtual (也叫PVSCSI)

这个vSCSI controller是能感知virtualization的, 并且是被设计来使用极小的处理成本来支持非常高吞吐量的. 所以说它是最高效的驱动.

性能上的区别呢?

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PVSCSI and LSI Logic Parallel/SAS are essentially the same when it comes to overall performance capability. PVSCSI, however, is more efficient in the number of host compute cycles that are required to process the same number of IOPS. This means that if you have a very storage IO intensive virtual machine, this is the controller to choose to ensure you save as many cpu cycles as possible that can then be used by the application or host. Most modern operating systems that can drive high IO support one of these two controllers.
Here’s a detailed whitepaper that takes a closer look at PVSCSI vs LSI Logic SAS for IOPS, Latency and Cost. While it does support that PVSCSI is more capable, keep in mind most customers are not producing 1 million IOPS so for real life the difference is negligible.

来源

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Which vSCSI controller should I choose for performance?

http://blogs.vmware.com/vsphere/2014/02/vscsi-controller-choose-performance.html

Achieving a Million I/O Operations per Second from a Single VMware vSphere 5.0 Host

http://www.vmware.com/files/pdf/1M-iops-perf-vsphere5.pdf