As mentioned in one of my prior posts, I had a server that kept remounting the hard drive as read-only because of filesystem problems. The problem it was encountering was an aborted journal, which was identified by fairly unambiguous language in the output from ‘dmesg’. The solution, of course was to rebuild the journal.
This one is a quick one. After looking around, this seems to be the easiest way to make a system beep to get your attention without having to install third-party packages.
I recently ran into a problem with a remote Linux install that caused the root filesystem to keep remounting itself as read-only in an attempt to keep from eating itself. Because the filesystem was read-only, I couldn’t change any permissions, install any ssh certificates into different accounts, reset passwords or any of the other standard ways I would get at the data I needed. Likewise, because this was a remote system, I couldn’t just boot into a different environment to read the data (there was also the fear that the drive might fail or that there might be data loss upon performing the diagnostics needed to fix the volume). The solution I came up with was using a named pipe over ssh to funnel data. This worked really well, but took a bit of looking around to figure out how to make it happen.
While I use Evernote to store notes and links to relevant information, I want to set up a more public repository of random things I want to keep track of that might also be helpful to others. These are probably going to be technical in nature more often than not, dealing with GNU/Linux, Arduino, Bitcoin, encryption, 3D printing, or whatever else I feel like.
If I post something that you have insight into, please don’t hesitate to comment with more information or corrections!