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Recent Linux kernels default to not using an IO scheduler with devices that support multiple queues, which includes NVMe SSDs but not SATA (at least through AHC
by wtallis 5y ago
Recent Linux kernels default to not using an IO scheduler with devices that support multiple queues, which includes NVMe SSDs but not SATA (at least through AHCI HBAs). Individual distros can override the kernel's defaults. However, I'm not sure the difference between no-op and mq-deadline IO scheduling for SATA SSDs would be big enough to matter for the purposes of this article's measurements.
- anarazel 5y agoIt's a really annoying proxy to determine the default configuration :(. There's plenty devices with multiple channels that benefits from the increased merging possible with a scheduler - particularly around writes, where a lot of consumer SSDs are weak. And conversely, there's plenty workloads on single queue devices that are hurt by the scheduler and some of the other heuristics that trigger for single queue devices...