I recently observed this strange behavior from a Dell PowerEdge 2950 with PERC 6/i RAID controller. – One drive member from a RAID-5 array was failed – I pulled out the defective drive and pop in a brand new drive – Strangely, it did not started to sync and after a few moment, the drive… Read More »
Here is a quick reminder about the default username and password for Dell DRAC out-band server management : Username : root Password : calvin
UUIDs (Universal Unique Identifier) for network interface card can be generated using the following command : uuidgen <DEVICE> Example : uuidgen eth0 Then you can add it to your NIC config file (assuming your interface is eth0) : /etc/sysconfig/network-scripts/ifcfg-eth0 Add/modify the following : UUID=<uuid>
Did your Qmail server failed to receive a message including an attachment and showing this output in the SMTP logs? policy_check: remote sender@domain.tld -> local recipient@domain.tld (UNAUTHENTICATED SENDER) policy_check: policy allows transmission qmail-smtpd: qq soft reject (mail server temporarily rejected message (#4.3.0)): MAILFROM:<sender@domain.tld> RCPTTO:recipient@domain.tld tcpserver: end 0000 status 000 In this particular case, the version… Read More »
It’s possible to tell the kernel of your Xen guest VM to synchronize or not the clock with the physical host machine. There are numerous reason why you would or not to use this feature (such as your guest VM is behind or forward the clock over time). To find out the current setting, simply… Read More »
VMware ESXi management IP/vSphere connectivity might become suddenly unavailable over the time or after replacing the network interface card. This can be easily resolved by removing the vmnic port groupe for the management network and add it back again to the vSwitch. You will need direct console access to the ESX shell to perform these… Read More »
Here is a quick how to force your network interface speed and duplex on RHEL/CentOS Linux. Make sure you have the network tools installed : yum install ethtool net-tools To apply the configuration without having to restart the network service or reboot your system, simply do this command with your settings : ethtool -s <INTERFACE>… Read More »
Having this error on your RHEL/CentOS 6 Web server or issuing “php -v” command? PHP Warning: PHP Startup: Unable to load dynamic library ‘/usr/lib64/php/modules/module.so’ – /usr/lib64/php/modules/module.so: cannot open shared object file: No such file or directory in Unknown on line 0 Then you probably have “php-mcrypt” module installed. Apparently, the “mcrypt.ini” file do not have… Read More »
Ending up with this kind of error booting a guest machine on your Xen hypervisor? Running: xm create /cloud/config/hjxmogr553e5jx Using config file “/cloud/config/hjxmogr553e5jx”. Error: Unable to connect to xend: No such file or directory. Is xend running? Fatal: Virtual machine has not been started on hypervisor Executing Rollback… The two possible causes would be the… Read More »
Monitoring your temperature hardware on Linux made easy with “lm_sensors“. On CentOS or RedHat Enterprise, you can easily install the software using Yum as followed : yum install lm_sensors Then, you need to configure the software to monitor your hardware. You will have to answer several YES/no questions to probe your system. Just do the… Read More »