Tag: Linux

kworker using cpu on an otherwise idle system

I have an old thin client that I upgraded to a home server by adding some additional RAM and storage. I noticed after a recent kernel upgrade that the system seemed sluggish at times, despite doing nothing in particular at the time. top showed that a kworker process was using CPU, not all of it,

Keep getting logged out from Selfoss on Debian

I’m running Selfoss RSS reader and loving it! One thing I don’t love is that it logs me out frequently (BTW, I’m running Apache php-fpm on Debian Jessie). But I think I found a solution. Try adding this to a file called .user.ini in the document root of Selfoss: [crayon-5c66e4e83c4af033974478/] The 604800 means one week.

Debian server DNS bogosity

Note: I’m running my Raspberry Pi as a server, and NetworkManager is not installed. I discovered that if you want to manually assign search and nameserver entries in your /etc/resolv.conf file, you can’t just add the relevant entries to static entry in /etc/network/interfaces: [crayon-5c66e4e83c560784144011/] For some unknown reason, the resolvconf utility will still attempt to

finger has a posse

Just saw this on One Thing Well, and it made me so nostalgic about my early years on *nix and the net. A weather service fed over the finger protocol. [crayon-5c66e4e83c627264640982/]

GNU xargs is missing the -J option. WHY!?!

I find that using an idiom like [crayon-5c66e4e83c69b612554033/] is so useful. It replaces the replstr (“%” in this example) with all the arguments at once, or as many as can fit without going over the system’s limit. I couldn’t believe it when I learned that the GNU version of xargs lacks this flag. Yes, it’s

Unison dependency hell

I would really like to rid myself of Dropbox, but all the alternatives I’ve tried are too bloated, beta- or alpha-quality stage, too complicated to set up, or just plain don’t do what Dropbox does (minus the sharing stuff, which I don’t care about). I don’t want btsync, it’s closed-source. Seafile is too complicated, and

Allow webapps to make outgoing requests

I was experiencing a pretty bad slowdown while trying to use the admin pages of a WordPress site recently. The load on the machine was quite low, so I began to suspect that it was trying to call out to external services (facebook, pinterest, etc) that might have been blocked by CSF (configserver firewall). I

Raspberry Pi can do fast video encoding

Yes, the Raspberry Pi can do fast video encoding. Of course you normally wouldn’t want to re-encode any video with an ARM processor, but that’s not what we’re going to do here. We’re going to leverage the GPU. I should point out before proceeding that the input formats for re-encoding are limited in this method,

Clone hard disk with rsync

I recently wanted to move a system over to a faster, larger SSD. I didn’t want to have to re-install an OS, figure out which old files to transfer over, and then re-configure everything. That’s not a fun time in my book. Here’s what I did (on a live system, yeah!) to clone my disk.

Fix for LFD error in syslog

I noticed that I was getting emails from LFD (part of the ConfigServer Firewall package) about failing to find some added check line it was sending to syslog. The syslog message looks like this: lfd[%d]: *SYSLOG CHECK* Failed to detect check line [%s] sent to SYSLOG Of course I’ve replaced the pid with %d and

Switching from APF to CSF

I was enjoying trying out APF on my Raspberry Pi, but I noticed that it wasn’t blocking repeat attackers the way I wanted it to. fail2ban was working the way it was supposed to work, but it only blocks temporarily, and I never figured out why the gamin back-end to continuously monitor log files didn’t

Fix the broken APF package on Debian/Ubuntu

The Debian / Ubuntu package for Advanced Policy Firewall (APF) seems a bit unmaintained. By default it won’t run without some initial tweaking. Note that they probably want everyone to just download and run the installer from their site nowadays, but that’s not how I roll (usually). [crayon-5c66e4e83cad6404185953/] In functions.apf, change the line [crayon-5c66e4e83cadf255629859/] to

sort -u versus sort | uniq

I just ran into an interesting situation with sort -u. I had generated a couple files with md5sum and they had a lot of equal lines in them. So I thought I would create a merged version.