Vault 2016

With recent kernels block and SCSI multiqueue support has been integrated, showing a big performance boost on high-performance devices. At the same time, there are some features which a missing from multiqueue. Most notably multiqueue does not have any I/O scheduler, and it doesn't support I/O merging.

With high-speed storage these features should matter less, as the hardware is supposed to be fast enough to offset any impact here. However, numbers supporting this are hard to come by.

To validate this we have been running performance tests with Emulex 16G FC cards and NetApp EF-650 storage.

In this presentation we will show the performance results when running a 4.4 kernel. We will be giving a comparison with the original (3.12-based) SCSI implementation as well as the current implementation, with both multiqueue enabled and disabled.