mjhjmtu

A few months back, I have set up a separate storage for my data on my linux server (running Ubuntu 17.10).

The way I set it up is as follows:

• 
  /dev/mapper/community--vg-root - primary drive - 60GB - mapped to /
  


• 
  /dev/xvdb1 - secondary drive - 100GB - mapped to /mnt/data
  

then, since I know I have many apps and data in: /opt, /var, /home and /root, I decided to use mount bind option, to move all the files to the new drive on /mnt/data. My /etc/fstab looks like this:

#<file system> <mount point> <type> <options> <dump> <pass>
/dev/mapper/community--vg-root / ext4 errors=remount-ro 0 1
/dev/mapper/community--vg-swap_1 none swap sw 0 0

# data - 100GB
/dev/xvdb1 /mnt/data ext4 defaults 0 1
/var /mnt/data/var none defaults,bind 0 0
/opt /mnt/data/opt none defaults,bind 0 0
/home /mnt/data/home none defaults,bind 0 0
/root /mnt/data/root none defaults,bind 0 0

The problem

Using df -h I get:

/dev/mapper/community--vg-root 53G 16G 35G 32% /
/dev/xvdb1 98G 61M 93G 1% /mnt/data

But using du -h in /mnt/data I get:

14G .

So I definitely know that my binds and mounting is working, but all the data still takes up space in root.

All data has been moved from primary to the secondary drive, and then mounted. So there is no data in /var, /opt, /root, /home on the primary drive.

Once I even had to remove some files, because the system was unresponsive due to log files taking up all the space in root (which they can't, because they are on a different hard drive).

Is there any way to solve this problem? The reason why I added a second drive was to prevent the root drive from being full and moving my precious data to another drive which was only for data.