De-duplication! That is the keyword and if your backup storage hardware does not support it natively you still need it. That is the focus of this article. So I wrote earlier about rsync backups and the strategies used in the backintime software. Having gotten a bit of time to work with it I hope to outline a method to do “snapshot” style backups using rsync. This gives us the ability to quickly and easily “roll-back” to a previous date and time. Additionally the management of our backups gets vastly simplified and the de-duplication that this brings saves a ton of space.
For years I have been using Rsync to backup my files on my Linux desktop and server. Looking at how easy and automated this solution is I decided to try to find a similar solution for my Android phone. Originally I accomplished the task using a PULL method, that is my Linux box would initiate an rsync script that would pull the data from the phone to the server. I used a popular ssh server for Android which ran as a service so that the client on the Linux Box could connect to the phone. This method worked quite well except it could only be used inside my home network. When on mobile, Verizon uses an “Internal” type IP address thus making it impossible to initiate an outside connection. A dynamic IP is also an issue. In order to get around these limitations I decided to use a push method initiated from the phone. This would allow a backup to occur anywhere either on wifi or mobile. Read more
Connecting to WPA encrypted wireless networks in Linux is relatively easy with the great GUI applications such as network-manager or WICD. My only issue is that these applications tend to fall apart when dealing with multiple networks or interfaces that need to be connected simultaneously. (Such as is the case in my lab.) Also there are many times when I don’t have access to a GUI environment. Such as when the GUI environment is not available, then dealing with an absolute base install prior to a GUI being installed, or when dealing with several bootable Linux based rescue tools. Recalling the steps necessary to make the connection to a WPA encrypted wireless network from the CLI is difficult for me (since I don’t do it often) so for a slew of reasons this script has proven to be a useful tool in my toolbox. Read more
When sync’ing data from source to destination I am a bit over paranoid with deletion. I am concerned that files might be deleted on the source by accident, that files might be deleted on the source due to some sort of corruption or simply that today’s deleted file is tomorrow’s needed data.
There are a ton of different strategies for dealing with this issue (especially when rsync’ing backups) but I worked for quite awhile with the belief that the info to be deleted should be backed-up prior to deletion. — Luckily rsync (with a touch of some commonly used shell commands) can do this quite well. Read more