On Tue, 08.02.11 16:54, Andrey Borzenkov (arvidjaar@xxxxxxx) wrote: > >> a) mdmon is perfectly capable of restarting, it is already used to > >> take over mdmon launched in initrd. The problem is to know when to > >> restart - i.e. when respective libraries are changed. This is a job > >> for package management in distribution. It is already employed for > >> glibc, systemd and some others and can just as well be employed for > >> mdmon. And this is totally unrelated to systemd :) > > > > Really, you are sying there is a synchronous way to make mdmon reexec > > itself? How does that work? > > > > I am not sure whether it qualifies as synchronous, but "mdmon > --takeover" will kill any existing mdmon for this and start monitoring > itself. I wonder if this is really fully synchronous, i.e. that a) there is no point in time where mdmon is not running during this restart and b) the mdmom --takeover command returns when the new daemon is fully up, and not right-away. > > Well, the root file systems cannot be unmounted, only remounted. > > > > So, is there a way to invoke mdmon so that it flushes all metadata > > changes to disk and immediately terminates then this should be all we > > need for a clean solution. We'd then shutdown the normal instances of > > mdmon down like any other daemon and simply invoke this metadata > > flushing command as part of late shutdown. > > > Hmm ... it looks like you just need to > > start mdmon > do mdadm --wait-clean > > After this you can kill mdmon again (assuming decide is no more in > use). Well, it would be nice if the md utils would offer something doing this without spawning multiple processes and killing them again. Lennart -- Lennart Poettering - Red Hat, Inc. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
