I should use this blog more. Here is one of the things might be useful for other admins I wrote meantime. This script generates a report, which includes all important information via ILO interface on HP servers (using python-hpilo package). Supports ILO2-3-4, which is a pretty good range for non-ancient servers I think. I've started to study golang as hobby, so might port this to Go later. But for now, this is really handy:
User gets a warning about disk, sees it's full and starts to investigate. After removing few GB's, there is a little problem: df and du commands' conflicting output. Where is my free disk? After searching it on Google, people says "check out lsof | grep deleted" and user realizes this is really a thing on Linux. Processes hold files on disk even the files are deleted. Restarts the process, and everything seems fine now.
If you have lots of physical servers, I totally understand if you don't want to talk about "upgrading" them. But you need to upgrade, at least the device firmware's should be decent so you don't see weird errors on higher levels. Well ok, you probably will see some weird things anyway but if you upgrade, the vendor won't be poking you with "please upgrade to latest firmware" for every problem.
Hello, In this rant, we'll install X software to Y system. You are here because you are a bit desperate finding the right package you need. Maybe the software and/or the system is a bit old. Let's start! First, download the software here: software.tar.gz Yes you saw damn right, a big blue TARBALL. You might not care about your system's file integrity and be a moron to not to think about that COMPILING thing!
New distros with cool ideas always amaze me. Too bad we generally have new shiny debuntu based software collections only. Bedrock is a different one. Here is a quote from official website: If one would like a rock-solid stable base (for example, from Debian or a RHEL clone) yet still have easy access to cutting-edge packages (from, say, Arch Linux), automate compiling packages with Gentoo's portage, and ensure that software aimed only for the ever popular Ubuntu will run smoothly - all at the same time, in the same distribution - Bedrock Linux will provide a means to achieve this.
Scripting under different unices is a bit painful. Especially if you have a completely mixed environment with plenty of obsolete systems in it. I was trying to get md5sum of something quickly. Here is the result: Sure, you can use md5sum command on every system if you install it, but this seems like the most painless way. Still failing on some old Solaris (like 8/9) but luckily I can skip those :)
My VPS on Contabo started to act funny, probably they overloaded their KVM hosts. I started to see messages like "[27941.674540] sh (9100): drop_caches: 3" on dmesg (totally not cool bro). So I've switched to DigitalOcean. Thanks to systemd-nspawn, moving entire system was really easy: rsync one big data file, mount it and start the container.
Seems like only reasonable way to use "dbx" tool (like dbx -a PID and issuing proc rlimit inside attached dbx). But somehow everyone just "quit"s dbx and sending SIGTRAP to process. Only if there is a way that you can "detach" before. Maybe this is new to AIX (probably came with 6, I'm still a rookie on AIXland) but it seems possible with "detach" command in dbx.
If you tried this topic and didn't help, you're probably using gentoo. I came across this bug with ~5.3.1. Stracing gave me following sequence: What the hell? Looking for kde pam module and skips right to "other", which denies auth without a question. If you have the same problem, try symlinking: ln -s /etc/pam.d/system-auth /etc/pam.d/kde
I've discovered systemd added a container utility called systemd-nspawn. It's basically chroot on steroids. (No, don't think Docker) I decided to give it a shot even they don't consider it stable yet. I tried to implement encryption a bit. Data normally sitting duck on bare-metal unencrypted servers (mainly because encryption seems hard or you trust your data center & country). If someone reboots the server and adds "rescue" to grub kernel line, (s)he will get a root user prompt, bye to personal/commercial sensitive info!