$ grep memory /lib/udev/rules.d/* /etc/udev/rules.d/*
/lib/udev/rules.d/40-vm-hotadd.rules:# On Hyper-V and Xen Virtual Machines we want to add memory and cpus as soon as they appear
/lib/udev/rules.d/40-vm-hotadd.rules:#SUBSYSTEM=="memory", ACTION=="add", DEVPATH=="/devices/system/memory/memory[0-9]*", TEST=="state", ATTR{state}="online"
I ran update-initramfs and rebooted again, but was still able to reproduce the error with dd
$ grep 0 /sys/devices/ system/ memory/ memory* /online system/ memory/ memory504/ online: 0
/sys/devices/
$ grep memory /lib/udev/rules.d/* /etc/udev/rules.d/* rules.d/ 40-vm-hotadd. rules:# On Hyper-V and Xen Virtual Machines we want to add memory and cpus as soon as they appear rules.d/ 40-vm-hotadd. rules:# SUBSYSTEM= ="memory" , ACTION=="add", DEVPATH= ="/devices/ system/ memory/ memory[ 0-9]*", TEST=="state", ATTR{state} ="online"
/lib/udev/
/lib/udev/
I ran update-initramfs and rebooted again, but was still able to reproduce the error with dd