Is FFXIV allows you to pause and resume the download?

I completed the trial version and bought the full game. However, I encountered an "unable to download patch files [30413][25008][10009]" error. I used a VPN to fix that issue, but now the problem is the download speed. It says I have to wait 2,115 minutes (literally 30 hours) to complete the download. Of course, I can't leave my PC on for 30 hours straight. Some people say FFXIV allows you to pause and resume the download, but others say it doesn’t. I’m not sure how to check if the download will resume or not. Yeah FFXIV is my first MMO.

The launcher does indeed remember where you left off downloading patches, however it has to take a few moments to check the files to see where abouts exactly it has (it actually installs individual patch files as you go along, it doesn't download it all at once and then only install it at once when downloading is completed, so it has to check for this), so don't worry!

Your internet connection may be at fault here though, it shouldn't be taking over 30 hours to patch even with DT's massive size and the previous expansion files as well. So your net speed is probably causing it to lag considerably (I still remember having to download FFXI's patch files on 56K dial-up internet back in the day, now that was fun.... ;)).

In my experience, if you close the launcher it will just resume where it can and be fine.

However, this does not work if, say, you go into your patch files and delete half of them. It won't resume in that situation, and will instead either try to launch the game without them or it will wipe all your patch files entirely and redownload them. This is because it remembers where you left off via the Documents folder and not via the game directory which contains the patch files. The game doesn't have a proper checksum search to see which files need patching, so if one is corrupt the safest thing to do is to redownload the whole game to prevent crashes.

As for keeping your computer on for 30 hours, I personally keep mine on for months at a time between reboots. It can be done and it's unlikely anything will happen, but it will affect your electricity bill, especially if games are running due to the GPU power draw.