> Il giorno 24 mag 2019, alle ore 16:46, Jeff Moyer ha scritto: > > Hi, Alexey, > > Alexey Dobriyan writes: > >> 5.0 deleted three io schedulers and more importantly CONFIG_DEFAULT_IOSCHED >> option: >> >> commit f382fb0bcef4c37dc049e9f6963e3baf204d815c >> block: remove legacy IO schedulers >> >> After figuring out that I silently became "noop" customer enabling just >> BFQ didn't work: "noop" is still being selected by default. >> >> There is an "elevator=" command line option but it does nothing. >> >> Are users supposed to add stuff to init scripts now? > > A global parameter was never a good idea, because systems often have > different types of storage installed which benefit from different I/O > schedulers. The goal is for the default to just work. > Just for completeness, the current default is the worst possible choice on all systems with a speed below 500 KIOPS, which includes practically all personal systems ;) But this is a different story ... Thanks, Paolo > If you feel that the defaults don't work for you, then udev rules are > the way to go. > > If you also feel that you really do want to set the default for all > devices, then you can use the following udev rule to emulate the old > elevator= kernel command line parameter: > > https://github.com/lnykryn/systemd-rhel/blob/rhel-8.0.0/rules/40-elevator.rules > > Cheers, > Jeff