Mounting a LVM partition from a QEMU file

Last week we had an interesting problem, one of our customers needed us to recover files from a KVM disk image. They had no idea how the disk had been partitioned or about the KVM it came from (on further inspection it would not boot). Like a set of matryoshkas dolls the raw image contained a GUID Partition Table, which contained a Logical Volume Group which contained the partition we needed to mount.

We started by trying to view the partition table using fdisk to gave us an idea of what was inside.


${fqdn} not working in puppet manifesto

When using ${fqdn} in your puppet manifestos to specify different config files for your nodes. often they will simply not pick up the correct file. 

  file { "/etc/sysconfig/iptables":
    ensure => "present",
    source => ["puppet:///modules/security/iptables.${fqdn}","puppet:///modules/security/iptables.default"],
    notify  => Service["iptables"], 

The iptables example above always gets the default iptables config file.

A lecture on backups and how to encrypt removable media

Golden rules of backups
- at least 3 copies.
- stored in atleast 2 different locations. 
- any removable media is encrypted. 
- if the backups have not been tested they do no exist. 
- RAID does not count as a copy. 

If you are using USB drives to backup your data, you have no excuse to not encrypt them. The handy procedure is exactly the same for USB sticks and is supported by all the main Linux distributions.

Create your very own home or small office "great firewall of Cameron".

The internet is all a buzz with the announcement of UK ISPs flicking the switch to "default on" filtering, "the great firewall of Cameron" . From a technical stand point there is very little detail on how they will be implemented other than probably being based on an openDNS and Huawei solution. 

Block adverts and speed up internet access with a proxy server

The days of speeding up internet access using a caching proxy server are pretty much over. The idea of caching is theoritically sound, but the majority of your proxy log is generally just "TCP_MISS", dynamic content having taken over the internet. All however is not lost, using access control lists with a proxy server you can improve the speed of web browsing along with the overall experience by blocking ads. The defacto open source caching proxy is squid.


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