After Changing Sharing Settings on Macbook, Bitcoin Core 26.0 Lost Sync with External Drive

Hey everyone, I'm feeling a bit lost here (which happens to me often). So, I tweaked my sharing settings to share internet through an ethernet cable to another computer, and then Bitcoin Core crashed. I rebooted my machine and Bitcoin Core, and while it said it was 'syncing', the next day I noticed it had downloaded all the data again. But now it looks like it's stored on my internal drive (which I just realized is about 700Gb fuller). What's weird is I can't figure out where those blocks ended up. I even searched for the blocks like blk00008.dat but came up empty. There’s nothing in ~/Library/Application Support/Bitcoin or at /Users/Library/Application Support/Bitcoin. I don't see any Bitcoin installation on my computer since I relocated everything to an external hard drive. Could it be that changing my network settings on the Mac redirected Bitcoin Core to save files somewhere completely different? Thanks a lot. S

I don't have a Macbook but let's see if I can give you some solution to your issue. Have you tried to search the folder instead of the block data? You can use the magnifying glass on the top right corner or use "Command + F" and type "blocks" The result should show two blocks folder if you are right that Bitcoin core created a new folder to resync or redownload the whole blockchain. If you already have downloaded blocks I suggest make or edit bitcoin.conf file and put manually the directory of your blockchain so that it won't redownload all data that you already downloaded before. You can find the bitcoin.conf under this directory below or you can find it on the GUI by going to settings>options and then open the configuration file Edit it with Notepad or software on a Macbook that can edit the file and paste this config below it's just a sample but you should replace it with your Bitcoin path folder and then save it and reboot Bitcoin core. If the blockchain is on a different path you can point it only the block folder use this parameter below

Thanks Yes have tried searching as suggested, but I don't have a Bitcoin folder in the addresses we've discussed on my internal drive... I can see that Bitcoin Core is running and saving the data to the internal drive in the Activity Monitor. However, I cannot find a single file. What would be good is a way of finding out the directory Bitcoin core is linked to. Can this be done at the Terminal/Command prompt? thanks

Your external drive might  be unmounted somehow when you share connection via ethernet cable, thus Bitcoin Core has started IBD from scratch. Check if external hard drive is still mounted, and head Bitcoin Core for the relevant directory on this drive where it could find the   previously downloaded blk-data.

Ok if you can't find it you should be able to find the right directory in the information tab of Bitcoin Core so to find the information tab open Bitcoin Core and go to Window> Information. You should be able to see datadir and Blocksdir under that it should be the data you looking for. Here's what it looks like Image source: https://bitcoin.stackexchange.com/questions/103295/unable-to-use-blocks-and-chainstate-from-external-drive

Not usually the case, unless it somehow broken the path to your default data directory and bitcoin.conf file where you set the custom datadir while the GUI's setting is set to default. In that case, it'll create a new "bitcoin" folder in the default datadir at the correct path and save the blockchain and other data there. (the folder may be hidden) If the custom datadir is set in the GUI's config instead (set in the Welcome Screen) and the path to "com.Bitcoin" somehow messed up by the network setting change, In the next restart of Bitcoin Core, the Welcome screen will prompt you again to set the data directory, if you didn't noticed and just clicked ok, it'll use the default internal drive.