3 ms·

Dropbox will work if you just create a local loopback file for an ext4 filesystem and mount the Dropbox folder on it.

algo646464 8y ago
The above is a great answer. To expand on this (from some googling). All of this requires root. 1) Create a sparse file (actual size depends on usage) truncate -s 100G /home/zzz/Dropbox.image 2) Create a ext4 filesystem on it mkfs.ext4 -m0 /home/zzz/Dropbox.image 3) Mount it as a loopback file system sudo mount /home/zzz/Dropbox.image /home/zzz/Dropbox-fs 4) Create / Copy your dropbox folder to Dropbox-fs sudo mkdir /home/zzz/Dropbox-fs/Dropbox sudo chown -R zzz.zzz /home/zzz/Dropbox-fs/Dropbox cp -r /home/zzz/Dropbox-original /home/zzz/Dropbox-fs/Dropbox 5) Start Dropbox and point it to the new location 6) If we want to mount this automatically at login. Adding it to /etc/fstab may not work because of encryption. But perhaps some script at login to mount it will work. For example, we can create a script at /usr/local/bin/mountDB.sh and then add a line to /etc/sudoers zzz ALL=(root) NOPASSWD: /usr/local/bin/mountDB.sh Then somehow call this script at login of user zzz.
- GordonS 8y ago
  I've never heard of a 'loopback filesystem' before. Can you expand a little on what this is?
  - prewett 8y ago
    It lets you mount a file as a filesystem, instead of an actual hardware device. I think it's called "loopback" because instead of reading from /dev/whatever it loops back to /dev/original and reads the specified file. See the man page for `mount`: https://linux.die.net/man/8/mount https://linux.die.net/man/8/mount (search for "loop")
  - Spivak 8y ago
    The right term is a 'loopback device' which allows you to use a file on an existing filesystem as a block device. Here's what the flow looks like: open(/path/to/myfile) -> ext4 driver -> block operations on /dev/loop0 -> open(/path/to/loop-file) -> block operations on the data region of the file -> btrfs driver -> block operations on /dev/sda

The above is a great answer. To expand on this (from some googling). All of this requires root. 1) Create a sparse file (actual size depends on usage) truncate -s 100G /home/zzz/Dropbox.image 2) Create a ext4 filesystem on it mkfs.ext4 -m0 /home/zzz/Dropbox.image 3) Mount it as a loopback file system sudo mount /home/zzz/Dropbox.image /home/zzz/Dropbox-fs 4) Create / Copy your dropbox folder to Dropbox-fs sudo mkdir /home/zzz/Dropbox-fs/Dropbox sudo chown -R zzz.zzz /home/zzz/Dropbox-fs/Dropbox cp -r /home/zzz/Dropbox-original /home/zzz/Dropbox-fs/Dropbox 5) Start Dropbox and point it to the new location 6) If we want to mount this automatically at login. Adding it to /etc/fstab may not work because of encryption. But perhaps some script at login to mount it will work. For example, we can create a script at /usr/local/bin/mountDB.sh and then add a line to /etc/sudoers zzz ALL=(root) NOPASSWD: /usr/local/bin/mountDB.sh Then somehow call this script at login of user zzz.

GordonS 8y ago
I've never heard of a 'loopback filesystem' before. Can you expand a little on what this is?
- prewett 8y ago
  It lets you mount a file as a filesystem, instead of an actual hardware device. I think it's called "loopback" because instead of reading from /dev/whatever it loops back to /dev/original and reads the specified file. See the man page for `mount`: https://linux.die.net/man/8/mount https://linux.die.net/man/8/mount (search for "loop")
- Spivak 8y ago
  The right term is a 'loopback device' which allows you to use a file on an existing filesystem as a block device. Here's what the flow looks like: open(/path/to/myfile) -> ext4 driver -> block operations on /dev/loop0 -> open(/path/to/loop-file) -> block operations on the data region of the file -> btrfs driver -> block operations on /dev/sda