4.11.1 Converting a Non-root File System

The software described in this documentation is either in Extended Support or Sustaining Support. See https://www.oracle.com/us/support/library/enterprise-linux-support-policies-069172.pdf for more information.
Oracle recommends that you upgrade the software described by this documentation as soon as possible.

4.11.1 Converting a Non-root File System

Caution

Before performing a file system conversion, make a backup of the file system from which you can restore its state.

To convert an ext2, ext3, or ext4 file system other than the root file system to btrfs:

Unmount the file system.
```
# umount mountpoint
```
Run the correct version of fsck (for example, fsck.ext4) on the underlying device to check and correct the integrity of file system.
```
# fsck.extN -f device
```
Convert the file system to a btrfs file system.
```
# btrfs-convert device
```
Edit the file /etc/fstab, and change the file system type of the file system to btrfs, for example:
```
/dev/sdb               /myfs          btrfs    defaults  0 0
```
Mount the converted file system on the old mount point.
```
# mount device mountpoint
```