daily system administration

Linux, Debian and the rest
any questions or comments: Tom@d7031.de

Apache 2.4 Backports for Debian wheezy and (squeeze)

Running Apache 2.4 (SID) under Debian wheezy and (squeeze) Apache 2.4 is the current major release. This version is available in the debian SID and Testing tree (experimental before), so I’ve backported these packages to wheezy and in the past squeeze. The last available squeeze-version for i386 in this repro is 2.4.4-6, because I’ve no squezze-i386 servers anymore and I can’t test this packages. The last squeeze-version for amd64 is 2. Read more →

Postfix and lost connection after DATA

Trouble with immature firewalls and postfix. I run into trouble with one postfix server. This server is located behind a firewall and I got the error postfix/smtpd[1434]: lost connection after DATA from … in the mail logs. Debugging postfix with debug IP-address shows nothing unusually. So it must be another reason for that. Searching around the first match is a problem with MTU and the absense of ICMP between the firewall and the postfix-server found on Heinlein Blog. Read more →

Using Apache2-module proxy_balancer as fallback solution for the backend

My servers are mostly work with a normal load, but sometimes they have stress. In some cases the content application like TYPO3 or TomCat could not handle the mass of requests. So I’ve been searched for a automatic solution to display a busy-Page. The Apache-Modul mod_proxy_balancer provides a solution for me. It doesn’t matter if the content is on the same machine or hosted on dedicated server(s) in the background. The difference is only the source loopback or some foreign IP addresses. Read more →

Apache webdav read write permissions

Howto grant different rights to users on webdav shares Using webdav is an easy way to share files over HTTP(S). The Apache Webserver has the modules included. The caveat is the grant concept inside DAV. Under Linux all files are owned by the apache user e. g. www-data, so it is not possible to work with file system rights like MS IIS. If the share ist read only or every autenticated user can write, no problem. Read more →

Monitoring Citrix Netscaler with Icinga/Nagios

Citrix Netscaler is a very good system for load balancing, if you want to have an enterprise system and not do this in another way with Apache for free. It also provide a access gateways for ICA sessions. It’s based on FreeBSD but it has no nagios-plugins inside like other firewall system e. g. GenuGate firewall systems. So the only way to monitor such device is over SNMP. There are some plugins on Monitorexchange to watch over CPU, Mem, Connections and Disks. Read more →