On Wed, 02.11.11 10:21, Williams, Dan J (dan.j.williams@xxxxxxxxx) wrote: > > That means we'd: > > > > a) patch systemd to check whether argv[0][0] of a process is '@' and > > owned by root and exclude it from killing on shutdown. > > > > b) patch mdmon to set argv[0][0] of itself to '@' iff it is running from > > the initrd. If it is run from the main system it should not set that and > > just be shut down like any other service. > > Well, there are two cases to consider: > > 1/ user starts the array manually and stops it with mdadm -Ss (mdmon > automatically shuts down). No need for a service mdmon just follows > the lifespan of the array. > > 2/ user starts the array but then expects it to be around until system shutdown > > In the latter case let the initramfs-mdmon takeover all arrays with > "mdmon --takeover --all". But if all arrays may eventually be > re-parented to an mdmon instance from /run, why not always start mdmon > from there? Well I am not sure how mdmon works, but let's say you booted up with an initrd lacking mdmon. Then, while the machine is up you set up a some md device, and start mdmon for that. At this point it will be independent of the initrd. But that should be OK since at shutdown time it can be detached cleanly without any special magic, too, since mdmon is not stored on that md device. So if you boot from md you need mdmon in the initrd. If you just use md outside of the root disk, then running mdmon as a normal service (i.e. one that is shut down like any other) should be perfectly fine. This why I suggested that only mdmon run from the initrd should set argv[0][0] = '@', because only that one needs the special handling that it cannot be terminated properly on shut down. The one running from the normal system can be treated like a standard systemd service. 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
