Julius Plenz – Blog

“nocache” in Debian Testing

I’m very pleased to announce that a little program of mine called nocache has officially made it into the Debian distribution and migrated to Debian testing just a few days ago.

The tool started out as a small hack that employs mmap and mincore to check which blocks of a file are already in the Linux FS cache, and uses this info in the intercepted libc’s open/close syscall wrappers and related functions in an effort to restore the cache to its pristine state after every file access.

I only wrote this tool as a little “proof of concept”, but it seems there are people out there actually using this, which is nice.

A couple of links:

My thanks go out to Dmitry who packaged and will be maintaining the tool for Debian – as well as the other people who engaged in the lively discussions in the issue tracker.

Update: Chris promptly provided an Arch Linux package, too! Thanks!

posted 2013-05-19 tagged linux and debian

dist-upgrade gnah

I'm not sure why, but AFAIR I've never done a dist-upgrade that was entirely successful. That is true to my Debian system at home as well as to various other Ubuntu systems I've laid hands on.

My Debian system was a mix of stable and testing packages, and somehow aptitude came to a point where it'd just not be able to resolve some dependencies, meaning I could not install nor remove any new packages. So I opted for a dist-upgrade to Testing. Here's how it went, roughly:

Now, what I ask myself: Manually patching a Perl module, manually resolving dependencies and invoking dpkg, being (momentarily) deprived of the few programs I use on a daily basis ... how will this packaging system ever be remotely feasible for someone who's not an expert of sorts and well-versed in debugging in a Unix wold?

Update: Some crap program said it depended on DECnet stuff. After a reboot, this caused the MAC addresses of all my interfaces (yes, both wireless and wired!) to be the same, i.e.: aa:00:04:00:0a:04. Solution is removing libdnet* and dnet-common. – You kidding me?!

posted 2011-08-24 tagged debian and rant