Linux

Cups PDF Filter Crashes

Problem: for some PDF files cups does not print the page, the web gui just tells “filter failed” and in the cups logfile you find [Job 528] PID 19521 (gs) crashed on signal 11! Discussion: cups on debian uses ghostscript as pdf renderer. The pdf renderer of ghostsciprt crashes on many files. You can test by simply running […]

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Autosave for VIM

I believe that it’s a good idea that vi does not auto save during editing. Think of config files or src files that should never be in an inconsistent state. The programmer or sysadmin should decide when he wants to save data. But sometime auto save is handy, while typing lists like todo lists or

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Rare Connection Resets after Linux Upgrade

Problem: after upgrading from Debian 6 to Debian 8 some of the machines lose their ethernet network connection under heavy load for some seconds rarely. You find lines like these in syslog: [2333099.217735] NETDEV WATCHDOG: eth1 (tg3): transmit queue 0 timed out [2333099.217966] tg3 0000:03:04.1 eth1: transmit timed out, resetting [2333099.384391] tg3 0000:03:04.1 eth1: 0: Host

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Compiling Sendmail on Debian7

Problem: after compiling sendmail on Debian7 with “./Build” sendmail does not recognize hash .db files. You see the following error message: readcf: map access: class hash not available Discussion: ./Build should detect the berkley DB automatically. When devtools/bin/configure.sh finds libdb.so it adds -DNEWDB as compile option. On Debian7 the libdb.so file moved to /usr/lib/x86_64-linux-gnu/ and configure.sh fails to

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Generate CSR using openssl

Browsers started to warn users about certificates with Sha1 signature. Sha256 is needed now a days. So it’s time to renew certificates from Thawte, Godaddy, etc You can generate a new Certificate Signing Request with openssl with this command: openssl req -nodes -newkey rsa:2048 -keyout servername.key -out servername.csr -sha256 “servername.csr” is an ascii file you can send

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Wget Ignores its Timeout

Problem: wget has an option to configure the timeout for dns, connect, and read or a combined timeout option “-T”. This option usually works, but it does not work during SSL handshake. You can test it with these commands: in one terminal start a dummy tcp service: nc -l 7777 and then try to connect to

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Openbox goes weird with R.A.T.5 Mad Catz

Problem: when you connect the Mad Catz R.A.T.5 mouse to a Linux box running openbox window manager, the window handling stops working. Sometimes mouse follow focus does not work, sometimes even  clicking a window cannot activate it. Sometimes clicking window borders does not work, sometimes clicking into windows is ignored. Solution: This mouse has a mode button, which is

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USB SCSI Disconnects when Idle

Problem: An external USB harddrive disconnects and immediately reconnects with different device name. You find log entries like these: Jan 17 00:46:52 workstation kernel: [212306.086568] sd 33:0:0:0: [sdj] Attached SCSI disk Jan 17 01:51:14 workstation kernel: [216168.064075] usb 2-4: USB disconnect, device number 11 Jan 17 01:51:15 workstation kernel: [216168.596514] usb 2-4: new SuperSpeed USB device

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