Photo credit: doug88888 (Flickr)
If you’ve jailbroken your iDevice and run Cydia then you’ll have, without realising it, backed up something called an SHSH blob. Whilst the term seems geeky and uninteresting, if you’re a jailbreaker it’s essential you stay on top of making sure your blobs are all saved. Without them, you might find yourself in a frustrating situation where you’ll wish you’d taken the time to learn about and care for these special fluffy sounding things.
Before we look how you can manually save these blobs (in case Cydia’s automatic provision goes offline again like in the Amazon EC2 outage of 2011) we should learn a bit more about them.Â What are these blobs I hear you ask? In simple terms, when you install iOS updates to your iDevices, iTunes phones home back to Apple to make sure the device you’re updating is authorised to install the firmware you’re attempting to load upon it. Apple do this to force people into updating their devices, Apple simply enforces this by stopping to “sign” old firmware once they release updates. That signature is known as the SHSH blob. Each time you open Cydia, a quick step executes in the background to see if the current firmware release blobs for your device have been saved, if not, they are requested from Apple and stored away on one of Saurik’s (Cydia’s owner) servers.
Some devices don’t use Cydia, for example the AppleTV, and sadly, even though it was never expected, the worst can happen and Cydia’s systems go down like during the Spring of 2011 when Amazon suffered 10 days of downtime on it’s EC2 platform. It’s therefore quite important to manually backup blobs using a third party tool like Tiny Umbrella. The tool has other uses, but we’ll come to those in good time. Before we get to them, let’s look at how you can manually backup your blobs and see what blobs are stored for a given device.
- Download the latest version of TinyUmbrella for Mac fromÂ here and PC version from here
- Double click the downloaded file, soÂ TinyUmbrella.pkg file for Mac users and TinyUmbrella.exe for Windows users, then follow the prompts to install the application
- Connect your iPhone to the computer and open theÂ TinyUmbrella application to launch the program.
- Make sure your iPhone is selected from the list on the left, then click theÂ Save SHSH button
- Once completed you will notice a new entry in theÂ Saved SHSHs for iPhone list confirming the successful save of your SHSHÂ blobs.
That’s it! Simple really considering that minature wall of text preceeding the instructions!
Tiny Umbrella has it’s other uses though. We’ve covered these off in another guide, How to: Downgrade your iDevice firmware using TinyUmbrella.