Monday, July 29, 2013

Upcoming changes coming to alex-ubuntu-server





 Recently a friend offered me a new server with much better specs than the 15+-year-old computer that I use now. It has 4GB of RAM (compared with the 256 MB that the current server has), and it has a dual-core AMD processor running at 2800MHz. I'm not sure what the processor specs are for the current server, but honestly, I'm sure they're just as crappy as the RAM.

Getting this new server will open up a lot of possibilities, so here's some important changes that are coming to the server, if you are the one person that uses it.
  • X11 forwarding will be installed and turned on for SSH connections
    • This means that if you have an account (i.e. are able to SSH into the current server), you will be able to remotely login to a graphical environment. This means that you can e.g. carry your graphical application settings around with you (or at least, it will seem like that, in reality you'll be loading them from my server, which will require internet access).
    • It's unknown if I will offer GNOME. I will be open to any lightweight window manager such as awesome, Openbox, Fluxbox, twm, etc., without further thought. However, I will have to experiment with what system load looks like with GNOME installed. Therefore, I'll start with GNOME, but you should be aware that GNOME could eventually be removed again.
  • LVM will be turned on and partitions will be reconfigured
    • This won't affect you in any measurable way if you use the server. It just means that if there's ever a need for more storage, there won't have to be server downtime in order to install and use it. If you don't know what LVM is, read the Wikipedia article on it.
    • /home will become a separate partition. This is mostly to allow for easier backups (currently there is zero backup policy) and easier transitions in the event of another server move.
  • There will be a fresh installation. I will not just be dding or rsyncing files over to the new install.
    • There are several reasons for this. The first and foremost is that I installed and set up this server a couple of years ago, back when I was around 11 or 12, and thus didn't know exactly what I was doing, and I didn't have a very good idea of how to be a sysadmin. Because of this I didn't really keep a record of changes that I'd made, and thus, I don't know exactly how the system is structured and cannot effectively perform changes or diagnostics (because I don't know how changes would affect the system).
    • I may or may not transition to Arch Linux as the distribution of choice for my server, and this requires a reinstall. At first blush this may seem like a bad idea, since Arch is rolling and you need stability for a server (this is why Debian and Debian derivatives are so good for servers - they're stable and don't change often). However, it's worth noting that with Arch, you can deal with problems as they come along, instead of all at once every 6 months. This is actually pretty useful, because you can tell exactly which package changes may have broken something, instead of 5-10 things potentially breaking all at once. In short, problems are isolated. Note that if I do run Arch on my server, I will of course do my utmost to maximize stability - for example, I'll use an LTS kernel instead of the latest. Another reason that I'm thinking of Arch is that it makes it easy for me to understand exactly what's going on. Ubuntu and Debian both come with batteries included, which is generally a Good Thing™ but can be unfortunate if you want to understand the exact composition of your system (which you should if you want to be a good sysadmin). In particular, Ubuntu and Debian are very generous when installing optional things (not helped by the fact that installing Recommends is turned on by default in the APT configuration). It gets to the point where the GNOME metapackage in Debian depends (not recommends - depends) on the AdBlock Plus XUL extension. What?? Finally, I just like Arch better than Ubuntu. pacman vs. apt-get, apt-cache, apt-mark, apt-cdrom, apt-<5 other things here>, anyone?
    •  LVM (see above) is much easier to set up with a fresh install.
    • Services operation will not be impacted. Anything that works on the server now will work in the new server. Primarily, this means mail and SSH access. I'll also ensure that a lot of currently-installed packages are still available (for example Emacs). If you encounter something that you could do before and can't with the new server, I will consider it a configuration bug and will fix it.
    • Note that the two exceptions to this is /home and /etc.
      • /home I will transfer over for obvious reasons: I don't want you to lose data. That being said, be cautious because configuration formats may change if I move to Arch.
      • /etc is version-controlled with etckeeper. Therefore I'll just add a remote and git push, but I may take the opportunity to do some pruning.
  • I will overwrite the current server setup with an installation of Plan 9 From Bell Labs, and I will set up that installation to be a private 9P server.
    • The new server will be set up to forward all incoming traffic directed towards 9p.strugee.net to the new Plan 9 server.
    • The Plan 9 server will run a Fossil filesystem backed by Venti, allowing rewinds, etc.
    • If you have an account on the main server you will have an account on the Plan 9 server (I'll either set up a script to make this happen or I'll just go into each server and create a new user twice).
  • Note: this means downtime.
    • Most likely this will happen in the coming weeks or even months. It won't take that long, especially because I'll basically need to swap out machines (I'll have configured the new server while the old server was running), but just in case of extended downtime, be aware.
In order to prepare please rack your brains to figure out if you have any files not in your home folder. If you do, please either move them to your home folder or make backups.
If you lose data, I will be able to recover it, but I don't relish the thought as I'll probably have to mess around will loops and mounts and stuff (see the second paragraph). Assume that there will be no backups.

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