On two recent Supermicro servers, typing reboot actually shuts down the server. Thanks to Google and this blogpost, http://major.io/2013/06/03/supermicro-x9scix9sca-server-does-a-shutdown-rather-than-a-reboot/ I no longer have this issue. Short story: just blacklist the module named “mei” and you’re good.
If you want to boot with DHCP/PXE/TFTP method and your DHCP is handled by a Mikrotik router and your TFTP server is on another server, then you need to set the next-server and boot-file-name parameters in the network definition. Do not try to set DHCP options (codes 66 and 67) and assign them to the network definition, it will not work. The same applies to the NTP servers option. So, do not do this:...
This weekend, I finally had time to install a few network cameras from Ubiquiti in my house. The goal was to replace the previous system, which was composed of cheap USB webcams and the software motion , that has been running for years. HP Proliant N40L I had a spare N40L lying around that I used as a storage server for my VMware lab, so I repurposed it to be my future one and only home server running file sharing, monitoring, etc and AirVision of course....
It has been explained many times over the internet, so I won’t cover that. One thing you have to pay attention to is, if you run snmptt as a daemon, be sure that it has the right to write to Nagios FIFO. On my Debian system, I had to run snmptt as nagios user. Then, when you convert the MIBs to snmptt.conf file format, sometimes it will fail because the MIB is not RFC compliant....
After a few hours spent trying to find why Ubuntu 12.04 would not download a preseed file while netbooting, I stumbled upon this bug https://bugs.launchpad.net/ubuntu/+source/casper/+bug/923219 . I needed to add “IPAPPEND 2” after the APPEND directive in the pxelinux config file. Great.
Last week, I saw an huge “spam” outbreak on my MX servers. Instead of ~200k rejected SMTP connections, I had ~3M connections and it was rising. This caused some minor issues with the frequent log parsing as the log file quickly grew. To reduce the log file size and also the DNS requests number, I decided to use fail2ban to drop the connections before they got to Exim. This is rather easy, just create/append /etc/fail2ban/jail....
If you use Varnish with an Apache server and analyze Apache log files (with AWstats or something else), you probably saw all requests were coming from 127.0.0.1 (or the IP address Varnish is on). You’ve probably forgotten to change the LogFormat you use. Fortunately, Varnish adds an header on its request to Apache with the remote IP address in it. Just replace “%h” with “%{X-Forwarded-For}i” in the LogFormat and reload your server....
I needed to install some incoming mail servers (MX servers) to filter emails before delivering them to customers servers. So the need is to accept mails for a fixed list of domains, check for viruses and spams, then route them to customers servers for delivery. The distribution is Debian 6, the mailserver is Exim. The antivirus check is done by ClamAV and the antispam with Spamassassin + Pyzor + Razor + DCC + DNSBL....
Just some thoughts and things I’ve done. The hardware is the following: the Microserver itself, 2x 4GB DDR3, one 16GB USB flash drive, some 2TB SATA hard drives, Logitech S-150 USB speakers, and a GT520 HDMI+DVI graphic card. Installation on USB flash drive. There’s an USB port on the motherboard, so I plugged a 16GB USB flash drive and installed Ubuntu to it. The filesystem is ext4 because I trust it a lot more than btrfs and because it seems it’s quite good on a flash drive (source , it’s old, I know)....
2012-08-13 Update: simple monitoring with Cacti. The goal I want to have a clean Wowza setup for a live streaming platform. The access to the streaming server will be open but every other service (management interface, ssh, web server, etc) will be firewalled. There will be usage reporting through awstats, monitoring through SNMP (performance) and Nagios NRPE (availability). Ubuntu Ubuntu installation I’ve done a standard installation, nothing fancy. Partitionning is done like this:...