oam/knowledge base/mount files as virtual file systems.md

Mount files as virtual file systems

TL;DR

# Create the file.
truncate -s '10G' 'path/to/file'
dd if='/dev/zero' of='path/to/file' bs=4MiB count=250K status='progress'

# Create the file system on such file.
mkfs.ext4 'path/to/file'

# Create the mount point.
mkdir 'mount/point'

# Mount the file system.
# The 'loop' option is optional.
sudo mount -t 'ext4' -o 'loop' 'path/to/file' 'mount/point'

Prefer truncate to dd to let the file expand dynamically and be resized (both larger or smaller) without damaging data with losetup and resize2fs.

Further readings

• dd
• truncate

Sources

• How do I create a file and mount it as a filesystem?