Comment Comment by pgaddict Damn, I copied the wrong command. I wanted to copy this one:fio --filename=/dev/md127 --direct=1 --rw=randread --bs=8k --ioengine=io_uring --iodepth=1 --runtime=120 --numjobs=1 --time_based --group_reporting --name=iops-test-job --eta-newline=1 --readonlyi.e. with iodepth=1 and numjobs=1. Because this is what "mimics" index scan (without prefetch) on cold data. More or less.The command I posted earlier does ~10GB/s on my RAID, which matches your data. parent pgaddict 8 months ago
fio --filename=/dev/md127 --direct=1 --rw=randread --bs=8k --ioengine=io_uring --iodepth=1 --runtime=120 --numjobs=1 --time_based --group_reporting --name=iops-test-job --eta-newline=1 --readonly
i.e. with iodepth=1 and numjobs=1. Because this is what "mimics" index scan (without prefetch) on cold data. More or less.
The command I posted earlier does ~10GB/s on my RAID, which matches your data.