On Mon, 11.07.11 17:16, Adam Williamson (awilliam@xxxxxxxxxx) wrote: > > On Mon, 2011-07-11 at 18:18 +0200, Lennart Poettering wrote: > > > > One command that starts multiple process/daemons of a particular service. > > > It as simple as that. > > > > I guess we have to agree to disagree on this. A lost chance for NFS, > > Well, two people have already pointed out it's perfectly possible to > achieve this even for the multiple service case by using a target. You don't really need targets for this really. A target is a nice abstraction that can be used to mean a lot of different things based on configuration. But I think in the NFS case this isn't even necessary. So what I am proposing is this. Split up the daemons, so that you have one unit file per daemon. Have the main NFS daemon unit file pull in all other required NFS deaemons via BindTo and backwards too to ensure that they ara always started/stopped together. The optional additional daemons hook in via nfs.service.wants/ links, via the usual [Install] in them section and "systemctl enable". Note that you can hook services into any other unit via .wants/ links (including .service units!), not just into .target units. Nothing stops you from placing "WantedBy=nfs.service" in a unit file, in fact I encourage you to. Or in other words: using a target is not the solution, but simply using the relatively powerful set of dependencies you can express in systemd unit files. Here's an example. let's say we have three nfs related services. The main daemon is in nfs.service, an auxiliary service always needed by it is nfs-mount.service, and a third service nfs-quota.service is optional. Then write this: In nfs.service: <snip> [Unit] Description=Main NFS Service BindTo=nfs-mount.service [Service] ExecStart=... [Install] WantedBy=multi-user.target </snip> In nfs-mount.service: <snip [Unit] Description=Auxilary but mandatory NFS service BindTo=nfs.service [Service] ExecStart=... </snip> In nfs-quota.service: <snip> [Unit] Description=Optional quota service for NFS BindTo=nfs.service [Service] ExecStart=... [Install] WantedBy=nfs.service </snip> Then if you run "systemctl enable nfs.service" the first two services will be started at next boot. If either one of them goes down the other one will too. If you on top of that run "systemctl enable nfs-quota.service", then this one will be started at boot too. If it goes down the other ones don't care, but if you start nfs.service all three will be started. Which is a pretty good behaviour. Of course, these service names are all made up, but I believe the actual existing NFS services are not unlike these three examples. Lennart -- Lennart Poettering - Red Hat, Inc. -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel
