Are extended attributes [xattrs] enabled by default on EXT4 partitions?

[molecule-eye]

When I installed Kubuntu I manually set up my own partitions. The root is on an EXT4 partition and /etc/fstab does not have user_xattr set as an option for the EXT4 partition. However, if I add some metadat to a file (e.g. a tag through Dolphin), it shows up using "getfattr -d <filename>". BUT, that attribute is not synced across my devices using dropbox, which claims to support xattr syncing. It IS synced across my backups using the -X option in rsync.

So, I guess my filesystem supports xattrs without setting user_xattr as an fstab option, and dropbox therefore doesn't sync them, contrary to what support staff tells me. Am I right?

(It would be pretty bad if Kubuntu devs didn't enable xattrs by default since KDE uses them for metadata (searching, etc.))

[SteveRiley]

Most distros, including the *buntus, enable user_xattr. You can verify this with:

steve@t520:~$ [B]sudo tune2fs /dev/sdc1 -l | grep xattr[/B]
Default mount options:    user_xattr acl

Extended attributes will persist across file systems that support them and when you use move/copy utilities that can read and write them. You will lose extended attributes if you move/copy to FAT, for example.

From https://www.dropbox.com/en/help/145:

If your Dropbox folder is on a FAT32 drive, unfortunately it is impossible to retain metadata when the file is moved or renamed.

Is your Dropbox folder on a FAT drive on any of your devices? For instance, your smartphone or tablet?

[molecule-eye]

Most distros, including the *buntus, enable user_xattr. You can verify this with:

steve@t520:~$ [B]sudo tune2fs /dev/sdc1 -l | grep xattr[/B]
Default mount options:    user_xattr acl

Extended attributes will persist across file systems that support them and when you use move/copy utilities that can read and write them. You will lose extended attributes if you move/copy to FAT, for example.

From https://www.dropbox.com/en/help/145:

Is your Dropbox folder on a FAT drive on any of your devices? For instance, your smartphone or tablet?

Thanks for the help. I had manually added the "user_xattr" option in my fstab even though it's enabled by default, as you've allowed me to confirm.

All my desktop devices synced on dropbox use EXT4. My android devices do not, but they are NOT synced anyway. The dropbox android app requires that you download the file to view it, and I NEVER upload from my smartphone to my dropbox folder. Also, the dropbox created xattr user.com.dropbox.attributes IS synced across devices (it appears), so I'm not sure why they don't sync all xattrs.

It would help if someone else could confirm whether dropbox syncing of KDE metadata on EXT4 devices works for them. Anyone?