This seems a bit strange to me... vde wants to write to /run/vde.ctl, not /run/vde. And sure enough, /run/vde.ctl is created on startup.

If you look at /etc/vde/vde-config.sample (which users should base their VDE config on) it defines two variables as follows:

VDE_SOCK="/var/run/vde/sample.sock" # control directory pathname
VDE_MANAGEMENT_SOCK="/var/run/vde/sample.mgmt" # path of the management UNIX socket

/etc/rc.d/vde will honour those settings when starting. So, I guess, the start script should create the directory part of what both those variables define.

@Dave Reisner: Did you start vde without any such configuration specified in /etc/conf.d/vde via the VDE_CONFIG variable?

I don't use the /etc/conf.d file, because I wrote my own systemd unit which doesn't reference it. vde is capable of creating the directory where the control socket goes, as shown in the code for vde_switch:

432 » /* resolve ctl_socket, eventually defaulting to standard paths */
433 » if (rel_ctl_socket == NULL) {
434 » » rel_ctl_socket = (geteuid()==0)?VDESTDSOCK:VDETMPSOCK;
435 » }
436 » if (((mkdir(rel_ctl_socket, 0777) < 0) && (errno != EEXIST))) {
437 » » fprintf(stderr,"Cannot create ctl directory '%s': %s\n",
438 » » » rel_ctl_socket, strerror(errno));
439 » » exit(-1);
440 » }

rel_ctl_socket is tied to the -sock option, which defaults to /tmp/vde.ctl for non-root, and /var/run/vde.ctl for root. Regardless, the specified directory is created for you.

It'd be interesting to see a stack trace of the startup to see why this fails for you.

I think the problem is that the code is capable of creating /run/vde.ctl/ but not /run/somedir/vde.ctl/

This might be acceptable for many reasons but the sample configuration file suggests that it should be capable of doing so. It's just one of those occasions where documentation and reality don't agree.

Not a show-stopper but likely to trip-up the unwary who follow the documentation and examples. No action required, I guess.

What an insane supposition...

$ sudo strace -e mkdir /usr/bin/vde_switch -tap tap1 -mod 660 -group kvm -sock /home/noclaf/vde.ctl
mkdir("/home/noclaf/vde.ctl", 0777) = 0
--- {si_signo=SIGALRM, si_code=SI_KERNEL, si_value={int=1113522544, ptr=0x7f62425f0170}} (Alarm clock) ---
^C

Looks like it's quite capable of making a directory wherever it pleases, just as the code shows.

I based my "supposition" on the fact that /run/vde/ did not exist as a directory when e.g. /run/vde/vde.ctl was to be created.

My understanding of mkdir(3p) is that it would throw either an ENOENT or ENOTDIR error under such conditions. In your example, did /home/noclaf already exist before execution?

Ah, right. When a fragment of the full path doesn't exist, you get an ENOENT because mkdir(3) has the behavior of mkdir(1) without the -p flag.

So, the only thing "broken" here is that parent directory is expected to exist, and "classic" /var/run wasn't mounted on tmpfs. If you wanted to deviate from the default, you would need to provide a tmpfiles.d fragment.