When iOS 8 is released tomorrow, Apple will stop signing iOS 7.1.2. Users will no longer be able to restore their device to iOS 7.1.2 through iTunes. If anything were to happen to your device, you could be forced to restore to iOS 8 and ultimately lose your jailbreak. There are some solutions like semi-restore and iLEX RAT that will be able to 'restore' your device, yet still preserve the jailbreak. Those tools should be used as a last resort, as some have reported mixed success.
If you want to keep your iOS 7.1.2 jailbreak, do not update to iOS 8 -- there currently is not public jailbreak available for iOS 8, and once you upgrade, you cannot downgrade back! If you were looking to restore your iOS 7.1.2 device soon and jailbreak it, we recommend that you do that before iOS 8 is released on Wednesday (tomorrow!).
If your device is on iOS 7.1.2 or lower, you can always just Pangu or evasi0n to jailbreak, but you cannot restore the device to anything other than iOS 8 (once iOS 8 is released).
Finally, we recommend everyone installs OpenSSH on their iOS 7 device if they are jailbroken. It could end up saving your jailbreak!
If you need instructions on how to jailbreak your device, check out our wizard here
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