On Thursday, November 7, 2013 9:55:11 PM UTC-7, Jeffrey Goldberg wrote: > I'm an old Unix/Linux guy who has been away from modern Linux distros for > a while. And I've simply found myself absolutely bewildered after ssh'ing > into my BBB. > > I simply need a pointer to where I can find information about command line > system admin for this sort of Linux distribution. As an analogy, I found > that for my Raspberry Pi running Raspbian, I could read about Debian admin > and package management. What should I be looking toward to understand > Angstrom (command-line) system administration. > > A specific question is where can I find more about systemctl? As an > example, I would like to know how sshd is started on my BBB (It runs just > fine). But I can't find an sshd.service file as the man pages would lead me > to believe exists. Nor do I find a "traditional" init.d file. (It was > /etc/init.d/README that told me to learn about systemctl.) And I even > desperately looked under xinitd.d. > > I feel like there must be some trove of documentation that I'm failing to > find. I have looked before posting here. > > I can always put some OS I'm more familiar with on a microSD, but I would > like to give Angstrom a fair chance first. >
I think learning systemd is worthwhile, as it is a much more powerful system than sysvinit. It's also the default init for Fedora, Arch, and several other big distros. Ubuntu uses an alternate init system called Upstart that is also more powerful and flexible than sysvinit. Both allow you to explicitly model the actual dependencies between services that run, so everything gets initialized in order but as quickly as possible. Upstart and systemd can both significantly cut down on boot time, but systemd goes even further by also taking on the role of inetd, which will open sockets on the ports that services will use in anticipation of starting the service, and hand the sockets over when the service is finished starting. You can use this to trigger the starting of services as well. For example, if you're tight on resources, you can have systemd listen on port 22 in place of a ssh daemon. It won't actually *start* the daemon until someone connects to the port, though. And if you have a service you've written that requires other resources to run, it will ensure your service will start as soon as those are available. I've spent a lot of time pulling my hair out trying to resolve nondeterministic startup issues in a systemvinit-based embedded system. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
