Makura no Soshi

I released my first CPAN module.

I finally played with libcrm114, a C library that implements several text classification algorithms. It is a potential replacement for the mailreaver.crm tool, which is the basis for my SpamAssassin plugin. Read the rest of this entry »

Yay, I received my 200th spam mail after I set up my own mailserver in January. – Now my SpamAssassin can use its Bayes classifier.  %-)

Mal ein Eintrag in Kategorie „Tools, die ich gerne schon früher gekannt hätte“: Subversion mit vendor branches um eine eigene Version fremder Software zu pflegen, zum Beispiel um eigene Bugfixes drinzuhaben.

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Da ich nun nicht mehr Admin an der Uni Potsdam bin, habe ich jetzt auch meine Domain auf einen anderen Server umgezogen. – Falls irgendwelche Probleme auffallen schreibt mir bitte.

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It is still one of the first questions when installing a unixoid OS: do you still need a swap partition and how big should you make it. In the old days™ this was an important question because disk space was expensive and the OS memory management had several constraints.

Today both memory and disks are cheap enough to make this question insignificant in many cases. One can usually buy enough memory to prevent swapping, and with terrabyte disks it makes no real difference whether the swap partition is 1 Gb or 4 Gb in size.

I still use the old rule of thumb and allocate twice the size of RAM for a swap partition. But the intention is not so much to swap memory pages but rather to always have enough space for kernel core dumps. My basic reasoning is:

1. In case of kernel errors I want to get a core dump.
2. A later RAM upgrade is relatively cheap and easy, thus probable over a system’s lifetime.
3. A later disk re-partitioning is more difficult, thus to avoid.
4. Disk space is cheap, allocating ≤ 5% for a mostly unused swap partition has no significant cost.

Note: This syslog entry is puzzling if the system has no program named try, but no cause for concern:

2011-11-19T01:31:21 frodo kernel: pid 47812 (try), uid 0: exited on signal 10 (core dumped)

Source of the program is Perl’s Configure script, which compiles its C library test cases into programs named try. And apparently amd64 systems need to use the function va_copy() because the test case without this function leads to a segfault.

Durch eine Verkettung von Zufällen konnte ich letzte Woche im Uni-Teilnetz in dem dieser Server steht einige Tage lang tcpdump laufen lassen. Dabei habe ich gerade eben noch den IPv6-Tag miterfasst und das ist auch der einzige Tag, an dem sich IPv6-Werte finden, die höher sind als die IPv4-Werte.

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erfassen wir doch mal die SpamAssassin-Scores…
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