Removing Received field in mail header with Postfix
If you want to hide email source, you can easily remove Received field in mail header using header_checks.
How to get the first day of last month, and the last day of last month in bash
DATE_FROM=`date -d "-1 month -$(($(date +%d)-1)) days" "+%F"`
DATE_TO=`date -d "-$(($(date +%d)-1)) days" "+%F"`
Migrating RRD between 32 and 64 bit systems
Today I need to migrate cacti from old machine to blade. I have hit the problem This RRD was created on other architecture. Old system was 64bit and new one was existing 32bit system. RRD's must be converted.
Zabbix-agent 1.8 for CentOS 5
I have found we are using at work some CentOSes and I need to monitor them. After some googling I've found zabbix agent version 1.8 for centos here or here. No need to compile.
Creating ssl certificates
How to generate ssl certificate? Use this four commands to generate self-signed certificate:
openssl genrsa -out server.key 2048
openssl rsa -in server.key -out server.pem
openssl req -new -key server.key -out server.csr
openssl x509 -req -days 3560 -in server.csr -signkey server.key -out server.crt
If you need ssl certificate signed by some CA (eg. Startssl, GoDaddy), just skip last step. Instead, you will upload certificate request (csr file) trought CA web interface to sign it.
Just installed Fedora 12
#uname -a
Linux iwik.vnet.sk 2.6.31.5-127.fc12.i686.PAE #1 SMP Sat Nov 7 21:25:57 EST 2009 i686 i686 i386 GNU/Linux
Zabbix-agent 1.8 for debian etch
There is change in zabbix-agent version 1.8, disk free space is returned in bytes. See 'Free disk space bug' in zabbix forum. This can cause problems when you want to use same template for debian lenny system with 1.8 zabbix-agents from backports and some still not upgraded etch systems. Backported 1.8 zabbix-agent for etch can be helpfull - you can find it here.