Wednesday, January 29, 2014

Configuring Supermicro IPMI interface NIC using ipmitool

Newer Supermicro IPMI interfaces come configured by default in “failover” mode which means that the IPMI will bind to either the dedicated IPMI NIC port or share with one the the machine NIC ports.
This can cause IPMI to come up on wrong NIC and hence be inaccessible if the dedicated NIC doesn’t detect a link.
You can use ipmitool to change this behavour
First query the current setting:
ipmitool raw 0x30 0x70 0x0c 0
The result will be one of the following
0x00 = Dedicated
0x01 = Onboard / Shared
0x02 = Failover

Next to configure it you can use one of the following.
For older models:
ipmitool raw 0x30 0x70 0x0c 1 1 0
For X9 motherboards:
ipmitool raw 0x30 0x70 0x0c 1 0
References for this can be found here:
http://www.supermicro.com/support/faqs/faq.cfm?faq=9829
http://www.supermicro.com/support/faqs/faq.cfm?faq=14417

Thursday, January 23, 2014

eth* and em*

https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Deployment_Guide/appe-Consistent_Network_Device_Naming.html

Monday, January 13, 2014

Difference bewteen Pylab and pyplot

Matplotlib is the whole package; pylab is a module in matplotlib that gets installed alongsidematplotlib; and matplotlib.pyplot is a module in matplotlib.
Pyplot provides the state-machine interface to the underlying plotting library in matplotlib. This means that figures and axes are implicitly and automatically created to achieve the desired plot. For example, calling plot from pyplot will automatically create the necessary figure and axes to achieve the desired plot. Setting a title will then automatically set that title to the current axes object:
Pylab combines the pyplot functionality (for plotting) with the numpy functionality (for mathematics and for working with arrays) in a single namespace, making that namespace (or environment) even more MATLAB-like. For example, one can call the sin and cos functions just like you could in MATLAB, as well as having all the features of pyplot.
The pyplot interface is generally preferred for non-interactive plotting (i.e., scripting). Thepylab interface is convenient for interactive calculations and plotting, as it minimizes typing. Note that this is what you get if you use the ipython shell with the -pylab option, which imports everything from pylab and makes plotting fully interactive.