Migrate your Dropbox folder from ZFS to an ext4 ZVOL

This month, Dropbox has dropped support for non-ext4 filesystems on Linux. On my Linux computer, my Dropbox folder was on a ZFS filesystem… If you want to keep Dropbox syncing, they force you to move back to Ext4… non-sense, but I didn’t find any other alternative. So what I did is create a ZVOL (volume), format it as Ext4 and move my Dropbox content to it.

Create a Dropbox ZVOL

Here I create a 27GB ZVOL called dropbox on my zpool zpool, format it as Ext4 and mount it temporarily as /mnt:

# zfs create -s -V 27G zpool/dropbox
# mkfs.ext4 /dev/zvol/zpool/dropbox
# mount /dev/zvol/zpool/dropbox /mnt
# chown adumont.adumont /mnt

Notice the # prompt: I run these commands as root.

Copy Dropbox content

Here I stop dropbox, and copy all the content of my Dropbox folder to /mnt:

$ dropbox stop
$ rsync -avx /home/adumont/Dropbox/ /mnt/

Notice the $ prompt: I run these commands as my non-root user.

Remount the Dropbox ZVOL in place

Now I unmount /mnt, I delete my Dropbox folder (no problem, we copied it to the zvol), and I create the mountpoint:

# umount /mnt
# rm -rf /home/adumont/Dropbox
# mkdir /home/adumont/Dropbox

Then I add the new filesystem (dropbox zvol) to my /etc/fstab and mount it:

# echo /dev/zvol/zpool/dropbox /home/adumont/Dropbox ext4 rw,relatime,stripe=2,data=ordered 0 0 >> /etc/fstab
# mount /home/adumont/Dropbox

Dropbox on ZVOL

Last step I start Dropbox, and it will pick the new filesystem as Ext4 (on a Zvol):

$ dropbox start


Written on November 8, 2018