Perc 6i Foreign Configuration

My sys admin arrived to find the box in a bsod or locked up state. Upon reboot we got the foreign config error. The box was an aged Dell Poweredge 2950 with a Dell Perc 6i RAID controller was reporting a foreign configuration present on the adapter.

Now we know this was a raid0 array using 3 disks. I know, I know, this is a horrible configuration that was inherited and should never be used if the data is important.

I knew the three disks present were the original 3 disks in the array. Using the raid configuration console accessible at boot using Ctrl-R I was able to inspect the configuration on the disk and controller.

The adapter reported a 2 disk configuration while the foreign reported 3 disks.

We choose to import the foreign configuration present on disk two of a disk 1,2,3 array.

Smooth as butter!



Palo Alto Export Configuration using TFTP

Export the Active Configuration ( running-config for Cisco folks )  to a TFTP store running on Ubuntu 14.

Jump into your Ubuntu box and install the tftpd-hpa package using apt-get.

#apt-get install tftpd-hpa

Configure a few properties of the TFTP daemon.

#vi /etc/default/tftpd-hpa



TFTP_OPTIONS=”-c -v –secure”

Create and chmod /var/lib/tftp to allow writing to this directory by group “others”.

mkdir /var/lib/tftp

chmod o+w /var/lib/tftp

Export the active configuration.

tftp export configuration remote-port 69 source-ip from running-config.xml to


Subnetting a class C address in your head

In our example we apply the subnet mask [ /25] to the network

Subtract 25 from 32 total mask bits to leave 7 unmask bits which give way to host bits. Find the total address, including subnet and broadcast, per subnet chunk by raising 2 to the power of unmask bits.

Remember 2^8 = 256

2^7 = (2^8) / 2 = 128

Count from 0 by increments found in your computed answer to 256.

In this case we established two subnets using the /25 netmask.

Subnet     First Host     Last Host     Broadcast

0                 1                      126                 127

128             129                 254                 255