Direct sync write benchmark

Worst-case durable write speed (no cache, sync each block); note: not an IOPS test

dd if=/dev/zero of=/data/ddtest bs=1M count=1024 oflag=direct,dsync status=progress; rm /data/ddtest
tool
dd2 commands
tags
dddiskperformancetroubleshooting

More dd commands

  • Clone disk with progress
    dd if=/dev/sda of=/dev/sdb bs=64M conv=noerror,sync status=progress

    Block-clone whole disk; conv=noerror,sync keeps copying past bad sectors as zeros

all 2 dd commands