Webinar On Demand

Understanding Storage I/O Under Load

Recorded February 22, 2022

View a Complimentary Webinar Sponsored by ScyllaDB

There’s a popular misconception about I/O that (modern) SSDs are easy to deal with; they work pretty much like RAM but use a “legacy” submit-complete API. And other than keeping in mind a disk’s possible peak performance and maybe maintaining priorities of different IO streams there’s not much to care about. This is not quite the case – SSDs do show non-linear behavior and understanding the disk’s real abilities is crucial when it comes to squeezing as much performance from it as possible.

Diskplorer is an open-source disk latency/bandwidth exploring toolset. By using Linux fio under the hood it runs a battery of measurements to discover performance characteristics for a specific hardware configuration, giving you an at-a-glance view of how server storage I/O will behave under load.

ScyllaDB CTO Avi Kivity will share an interesting approach to measuring disk behavior under load, give a walkthrough of Diskplorer and explain how it’s used.

With the elaborated model of a disk at hand, it becomes possible to build latency-oriented I/O scheduling that cherry-picks requests from the incoming queue keeping the disk load perfectly Balanced.

ScyllaDB engineer Pavel Emelyanov will also present the scheduling algorithm developed for the Seastar framework and share results achieved using it.


Avi Kivity, CTO, ScyllaDB

Avi Kivity is known mostly for starting the Kernel-based Virtual Machine (KVM) project, the hypervisor underlying many production clouds. He worked for Qumranet and Red Hat as a KVM maintainer until December 2012. Avi is now CTO of ScyllaDB, bringing high throughput to the NoSQL world.

Pavel Emelyanov, Principal Engineer, ScyllaDB

Pavel “Xemul” Emelyanov is an ex-Linux kernel hacker whose past experience includes containerizing Linux and the foundation of the project called CRIU. Pavel joined the ScyllaDB core team at the end of 2019 (which probably explains some extra throughput brought to the NoSQL world since then).