Encrypted containers, modernized

dblspace revives the spirit of classic disk compression with modern cryptography and hidden volumes.

Create a single-file vault, mount it like a drive, and keep a hidden volume safely tucked inside. Built with modern encryption, CKFS2 compression, and cross-platform FUSE support.

Download v0.1.0 Read the manual What is dblspace? GitHub

Quick start

$ dblspace create -file vault.db -size 1G
$ mkdir -p /mnt/dbl
$ dblspace mount -file vault.db -mountpoint /mnt/dbl
$ dblspace info -file vault.db --prompt

Hidden volume protection: --hidden-passphrase

A compressed past

DoubleSpace, Stacker, and the race to shrink disks

1990-1992: The Stacker spark

Stacker pioneered real-time disk compression on DOS, promising more storage without new hardware. It quickly became the benchmark for "soft" compression.

1993: DoubleSpace arrives

Microsoft shipped DoubleSpace with MS-DOS 6.0. The feature was impressive but controversial, triggering a high-profile rivalry and legal battle with Stacker.

1993-1994: The Stacker verdict

Courts found DoubleSpace infringed Stacker patents, forcing Microsoft to pull it from MS-DOS 6.21 and rethink the product.

1994+: DriveSpace takes over

DoubleSpace returned as DriveSpace in MS-DOS 6.22 and later Windows, evolving the idea while the compression era gradually faded.

Rivalry as a design lesson

Compression isn't just about saving bytes. It's about trust: does the system preserve what matters? dblspace takes the nostalgia of DoubleSpace and the caution of Stacker to build a modern, verifiable vault.

Downloads

Grab a release binary

github.com/dblspace/dblspace/releases/

macOS (Intel) dblspace-0.1.0-darwin-amd64 macOS (Apple Silicon) dblspace-0.1.0-darwin-arm64 Linux (x86_64) dblspace-0.1.0-linux-amd64 Windows (x86_64) dblspace-0.1.0-windows-amd64.exe

Modern dblspace

From compressed drives to encrypted containers

Hidden volumes

Create an outer volume and an optional hidden volume. Mount the outer volume with hidden protection to avoid overwriting the hidden space.

CKFS2 compression

Chunked zstd compression keeps your data compact inside a fixed-size container. The logical size defaults to 2x for an overcommit-style experience.

Cross-platform

FUSE on macOS/Linux and WinFsp on Windows. Mount a single file as a filesystem with predictable CLI workflows.

Strong encryption

The container is encrypted using modern primitives. No keys leave your machine; your passphrase derives the encryption key.

Usage manual

Everything you need to run dblspace

Install

Grab the release binary for your OS and put it on your PATH.

chmod +x dblspace-0.1.0-darwin-arm64
mv dblspace-0.1.0-darwin-arm64 /usr/local/bin/dblspace

Create a container

dblspace create -file vault.db -size 1G
# add a hidden volume
dblspace create -file vault.db -size 1G -hidden-size 200M

Mount and protect

dblspace mount -file vault.db -mountpoint /mnt/dbl
# protect the hidden volume
dblspace mount -file vault.db -mountpoint /mnt/dbl --hidden-passphrase

Adjust compression target

Default is 2x logical size. Tune it for your data.

dblspace mount -file vault.db -mountpoint /mnt/dbl -logical-multiplier 3

Inspect a container

dblspace info -file vault.db --prompt

Unmount

# macOS
umount /mnt/dbl
# Linux
fusermount -u /mnt/dbl

Security reminders

Keep backups of your container file.
There is no recovery if you lose the passphrase.
Always mount outer volumes with hidden protection when needed.