'Twas brillig, and Chris Murphy at 16/01/14 15:34 did gyre and gimble: > > On Jan 16, 2014, at 8:25 AM, Kay Sievers <k...@vrfy.org> wrote: > >> On Thu, Jan 16, 2014 at 4:19 PM, Lennart Poettering >> <lenn...@poettering.net> wrote: >>> On Thu, 16.01.14 16:14, Zbigniew Jędrzejewski-Szmek >>> (zbys...@in.waw.pl) wrote: >>> >>>> >>>> On Thu, Jan 16, 2014 at 03:51:02PM +0100, Lennart Poettering >>>> wrote: >>>>> On Wed, 15.01.14 20:20, Zbigniew Jędrzejewski-Szmek >>>>> (zbys...@in.waw.pl) wrote: >>>>> >>>>>> I was a bit surprised that for mount points the dependency >>>>>> Before=local-fs.target is only added when nofail is not >>>>>> used. This seems to be a concious decision (added by >>>>>> Lennart in 155da457, and then survived all the refactorings >>>>>> by Tom and Thomas...). Do we still want this behaviour? >>>>> >>>>> Well, "nofail" means that we shouldn't bother if the device >>>>> doesn't show up at boot. Now, if we add "After=" for it >>>>> there, then we will time-out on it (though not fail) if >>>>> something else pulls it in. >>>>> >>>>> I figure this is a question what nofail really should mean: >>>>> "never wait for it, never fail for it" (which is the status >>>>> quo), or just "usually don't wait, never fail for it" (which >>>>> would be the change if we added After= in). I am tempted to >>>>> say that the status quo is more likely what people would >>>>> expect, no? >>>> >>>> The problem is that with current boot speeds, "usually don't >>>> wait" means that it shows up at some "upredictable" time. With >>>> a bit of luck, users might be able to log in before such mount >>>> points which are declared in /etc/fstab are mounted. I think >>>> that's unexpected, because it goes againt the general rule that >>>> things declared in /etc/fstab (w/o automount or noauto) are >>>> mounted at boot. >>> >>> I'd argue that "nofail" is precisely what the admin can use to >>> *enable* this race. If it should be avoided to allow the user to >>> log in before the device has shown up and is hooked in the admin >>> should not have used "nofail"... >>> >>>> I'd prefer to keep things orthogonal. This feels like an >>>> "optimization" that it user visible. We should rather encourage >>>> people to use automounts if the don't want to wait for the >>>> mountpoint to come up. >>> >>> I am pretty sure people would be annoyed by this change of >>> behaviour, simply because every boot would still delay for 90s if >>> the device is not plugged in. I have the suspicion that people >>> would really assume that using "nofail" would make their system >>> boot-up cleanly, without delays if the file system cannot be >>> found -- and that expection is something we'd not fulfill? >> >> man mount 8: nofail -- Do not report errors for this device if it >> does not exist. >> >> Right, we cannot really re-define this. It's use is established >> since years. Used for things like isci, which is often not >> available at bootup. > > > Although with faster boot times, a device in fstab not existing is > probably increasingly common. What about splitting the scheduling of > .mount jobs such that /sysroot happens early, and everything else > listed in fstab happens much later, to give the underlying device > every opportunity to appear before the attempt?
Primarily because special casing things is evil. Perhaps it would be better to just use a much smaller timeout for these generated units? Perhaps combine that with some kind of automount magic and then we've done all we can? Col -- Colin Guthrie gmane(at)colin.guthr.ie http://colin.guthr.ie/ Day Job: Tribalogic Limited http://www.tribalogic.net/ Open Source: Mageia Contributor http://www.mageia.org/ PulseAudio Hacker http://www.pulseaudio.org/ Trac Hacker http://trac.edgewall.org/ _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
