Having issues and downtime after installing latest updates using “yum update” is always a possibility. This is why having a development environment is so much important when you are running a mission critical infrastructure. However, there is an intermediate solution : using the rollback feature included in Yum. Note this option is actually not enabled… Read More »
I rescently experienced this issue with OpenFiler which I never had before. Trying to create a volume into a block device simply don’t work – nothing happen when you click to do so. The only difference between this installation and the previous one is the OpenFiler system is installed on another drive/block device than the… Read More »
Here is a quick tip how to install VMware Tools on the OpenFiler SAN Linux distribution. OpenFiler is based on rPath Linux. Since there is no binaries provided by VMware for guests tools, the first way is to compile them from source using gcc. But, rPath do have Open VMware Tools in their repository, so… Read More »
A few utilities are available to test the disk I/O performance. The easy way to do it without installing anything on the system would be running this simple command : time dd if=/dev/zero of=/tmp/test-hd bs=1M count=1000 Another, more complete tool I recommend is “SysBench”. http://sysbench.sourceforge.net/docs/
Lost your root password for MySQL? Follow this simple procedure to reset it. Of course, you need at least root access level on your operating system to proceed. 1. Stop MySQL database server : /etc/init.d/mysql stop 2. Start MySQL with “skip grant table” option : mysqld_safe –skip-grant-tables & WARNING! This is VERY insecure – while… Read More »
To detect if there is a link or not on network interface without any physical intervention, simply run the following command : cat /sys/class/net/<interface_name>/carrier This command should return ” 0 ” or ” 1 “. Of course, 0 mean disconnected and 1 connected.
Microsoft RDP (Remote Desktop Protocol) use the standard TCP-3389 port. To change this port to non-standard, there is no GUI to achieve this. You need to manually edit the registry to proceed. 1. Open the Registry Editor : Start > Run Enter “regedit.exe” *You may directly type this command in the Search bar at the… Read More »
If you have a full subnet to add on RHEL/CentOS Linux system, there is a short way to achieve this instead of manually create single alias interfaces. 1. Create a script at this location : vi /etc/sysconfig/network-scripts/ifcfg-eth0-range0 (ajust values as needed, according to the interface you would would have the IP subnet binded to an… Read More »
JSON support come natively with PHP 5.2 and later. If you are running CentOS Linux 5, this is PHP version 5.1.6 that is included by default. Fortunately, since version 5.6, CentOS packaged version 5.3.3 of PHP that can be installed through YUM (not included in the ISO set). If you still run applications that can’t… Read More »
Migrating Parallels Virtuozzo virtualization software containers from two remote master hardware nodes can’t be done using the hot migrate function included in the control panel. The migration must be done manually for each containers or virtual machines you want to move. Here is a simple procedure how to proceed : 1. You MUST first completely… Read More »