Getting worse and worse in this week run-and-also-test my Debian Web server. It was somewhat strange that I got failed file system operation in only about half day after file system repairment. Beside that, some applications crashed into segmentation fault and made system unstable. Two most frequent problematic applications were Spamassassin and Jdresolve, which coincidentally were invoked by cron. I tried to debug both of them by executing individually with their proper privilege (for example Jdresolve from www-data account), but still problem arose.
Another way I did was to reinstall some of applications/libraries which I suspected corrupt or misconfiguration. Debian's apt-get install --reinstall is a very helpful command for doing that. But no better result at all!
So I came into an conclusion to reinstall Debian, by first fixing backup script to make it easy saving valuable files in tar format inside safe partition (i.e. FAT32 partition). Finally, on Friday, 13 February I reinstalled Debian again, with one fault I made inside backup script: /var/log/apache is forgotten included.
Today Debian runs in second run-and-test with very limited packages. XWindows is not yet installed and Apache's log is used but untouched by such as log analyzer applications. Yet really, I missed previous one week Apache's log.