How can I use my Windows-formatted external drive with a Macbook too?

December 12, 2016 4:42 PM

Can I format/partition it for both systems without losing all the data I've already backed up on it?

Is this even possible?

I know you can format a new, empty drive to do this (exFat? Fat32? Sth like that, right?), but can I do it with a drive that already has a bunch of crap on it?

If you haven't already guessed, I'm a blithering idiot, so dumb it down if you can. Like, make it dumb, then go dumber. When you think it's dumb enough, dumb it down even more.

posted by Joseph Gurl to Computers & Internet (8 answers total)

Is there some reason you think your Mac won't read your current drive as it is? I have had drives that only a Mac can see, and drives that are formatted that both can see. I've never had a drive that only a windows machine can see and read to.

All my drives are formatted for Windows so that I can use it with both. I have no issues. Are you sure there is a problem that needs fixing, here?
posted by Brockles at 4:54 PM on December 12, 2016

The existing format on the drive may be FAT of some kind (in which case the Mac can read and write to it without a problem) or NTFS, in which case it may be able to read it but not necessarily write to it. There's various ways you can enable writing to NTFS.
posted by Candleman at 4:59 PM on December 12, 2016

I think JG wants to read and write to it, which means NTFS is a no-go without going to lengths on the Mac side.

There are utilities that will shrink an NTFS partition (down to the size its files are actually using, of course). It's been a while since I needed to do this, but I think PartitionMagic might have been one. Some Linux boot discs. For all I know, Windows might be able to do it on its own these days. But really the safest thing to do is offload the data, then reformat and/or re-partition, then copy the data back.
posted by snuffleupagus at 5:01 PM on December 12, 2016

To answer your exact question of "can I format a drive while still keeping stuff on it" the answer is no, you cannot. You'd need to copy that stuff somewhere else, format the drive, then copy it back.

Candleman has your answer for the question of "can I use this Windows-formatted drive with a Mac".
posted by Aleyn at 5:03 PM on December 12, 2016

Well....you can shrink the NTFS partition, create a temporary FAT32 partition, copy the contents of the NTFS partition to the temporary FAT32 partion (presuming they'll fit), reformat the NTFS partition to whatever, copy the data back, delete the temp partition, and then grow the remaining partition to consume all the free space again.

But really, just back the data up, reformat the drive, then restore it.
posted by snuffleupagus at 5:05 PM on December 12, 2016

I recommend against shrinking partitions, moving data and then rejiggering and embiggening (technical terms) the remaining partition. Usually, this stuff works well, but if you don't have a backup of your data and something goes wrong, you've lost it.

A 1TB drive is $55. A 5TB drive is $120. Just buy another drive and copy the data to it, then reformat the original. It's better to have your data in two places anyway.
posted by cnc at 6:24 PM on December 12, 2016 [2 favorites]

Best answer: The lengths you need to go to in order to read and write to NTFS from a Mac are, well, not that long if you are willing to drop some coin. My 2TB externals came with a free license for Paragon NTFS for Mac, and it works so well that I forget it's there, and whenever I reformat I forget, panic that I can't access my drives, go to the manufacturer's site, am reminded that I got a free license of Paragon NTFS for Mac, reinstall it, breathe a sigh of relief, and then promptly forget about it again.
posted by BrunoLatourFanclub at 9:15 PM on December 12, 2016 [4 favorites]

Nthing Paragon.
posted by uberchet at 6:50 AM on December 13, 2016 [1 favorite]