Dropbox Client Will Only Support Ext4 Filesystems On Linux Beginning November 7, 2018

Beginning November 7, 2018, the Dropbox client will only support the Ext4 filesystem on Linux. The news, coming from the Dropbox forums, mentions that the only supported filesystems will be Ext4 for Linux, NTFS for Windows, and HFS+ or APFS for Mac.

Dropbox users have begun receiving notifications about this, which mentions: "Move Dropbox location. Dropbox will stop syncing in November" without any further details.

If you get this notification and you're currently using a supported filesystem, you may have a computer linked to your Dropbox that's running on an unsupported file system. If you no longer use that computer, you can unlink it from your Dropbox account from here.

Update: A Dropbox support member has also confirmed to a Dropbox user that 
LUKS / ecryptfs on top of an Ext4 filesystem will not be supported either.

For why this is happening, the forum post mentions the following:

A supported file system is required as Dropbox relies on extended attributes (X-attrs) to identify files in the Dropbox folder and keep them in sync. We will keep supporting only the most common file systems that support X-attrs, so we can ensure stability and a consistent experience.

What's interesting here is that there are numerous Linux filesystems that support xattr (extended attributes) when enabled in the kernel configuration besides ext4, including ext2, ext3, Btrfs, XFS, JFS, and others.

If you're looking for Dropbox alternatives with full Linux support, you could run your own Nextcloud instance or use a Nextcloud provider. SpiderOak is also a nice alternative (it's not open source, but it uses encrypted cloud storage and client-side encryption key creation).

You also have the following alternatives:

Dropbox logo image credits: Wikipedia; news from Reddit.