Posts Tagged ‘RedHat’

EPEL NSD RPM and the missing PID file directory

Sunday, June 26th, 2011

NSD is a fantastic authoritative nameserver from NLnet Labs which was developed in conjunction with the RIPE NCC to be a highly scalable, secure authoritative nameserver which has no recursive features by design. In fact, it is such as good nameserver that it is used on three of the root namesevers (k.root-servers.net, h.root-servers.net and l.root-servers.net).

Thanks to the EPEL project run by the Fedora guys, you can quickly and easily install an up to date copy of NSD on CentOS/RHEL systems. The only problem that I have found so far is that the RPM doesn’t seem to create directory for the PID file specified in the /etc/nsd/nsd.conf and so the daemon won’t start out of the box.

Obviously it is easy enough to create the /var/run/nsd directory with mkdir, but remember to chown/chgrp this directory to the nsd user and group, otherwise and “nsdc restart” will fail with errors in /var/log/messages along the lines of “failed to unlink pidfile /var/run/nsd/nsd.pid: Permission denied“

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Posted in Red Hat and CentOS | No Comments »

Intel VT Virtualisation Technology on Dell PowerEdge servers

Saturday, June 19th, 2010

Somewhat annoyingly, Dell seem to like to disable Intel’s VT (Virtualisation Technology, sometimes called VMX) in the BIOS on their Dell PowerEdge servers, which means that you can’t use the Xen hypervisor to virtualise Microsoft Windows Server without changing this setting, which requires a reboot of the server to take effect.
You can use omreport from the Dell OpenManage Server Administrator software to check whether or not you have Intel Virtualisation Technology enabled.
If you haven’t got OpenManaged Server Administrator installed, then you can enable the Dell yum repository for CentOS/Red Hat systems and install it with:

wget -q -O – http://linux.dell.com/repo/hardware/latest/bootstrap.cgi | bash
yum -y install srvadmin-base
/opt/dell/srvadmin/sbin/srvadmin-services.sh start

Once you’ve got the Dell OpenManage Server Administrator services running, you can take a look at what processor is installed in your system and what the current BIOS settings are with:

omreport chassis processors
omreport chassis biossetup

The two attributes that you’re looking for are Processor Virtualization Technology (which needs to be enabled) and Demand-Based Power Management (which needs to be disabled).

If you need to change them, then you can do this with:

omconfig chassis biossetup attribute=cpuvt setting=enabled
omconfig chassis biossetup attribute=dbs setting=disabled

Once that's done, then verify the new settings by running omreport chassis biossetup again and then once you’ve rebooted the server you can start taking advantage of the hardware virtualisation provided by Intel’s Virtualisation Technology.

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Posted in Red Hat and CentOS | No Comments »