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I am using Ubuntu 13.10, and looking forward for the launch of Ubuntu 14.04 LTS. Please suggest me how should I upgrade to 14.04 LTS?
I have been running both 12.04 LTS and 13.10 for some time.
The recent Ubuntu versions (12.10, 13.04, and 13.10) have not always been stable (graphics drivers, obscure USB devices, CD/DVD playback, etc.). There have generally been no such issues with Ubuntu 12.04 LTS.
Initial testing (last 10 days) suggest that (apart from a few glitches on new features) this upcoming release will be as good as 12.04 LTS.
Wait three more weeks, and then migrate (or do a fresh install).
The proper way is to set the option of upgrading to new releases in your software settings.
Open the Software Centre and go to the Edit menu. Click 'software sources' and then the 'updates' tab. Set 'Notify me of a new Ubuntu version' to 'For any new version' and, with luck, your upgrade will go ok as part of normal updates.
Here's some advise on upgrading from Ubuntu :
It is probably wise to download 14.04 onto a dvd or usb before you attempt the upgrade, just in case you need to do a fresh install. So, like the page says, make sure you back up any valuable data.