Network Block Device Server written in Rust. Currently in alpha stage. See Disclaimer.

Main purpose of this project is to extend the capabilities of NBD Protocol. The same NBD Protocol you know, on steroids. Some of the extended features are:

• Chainable backends (i.e. Cache, Retry)
• Pluggable backends (Block: Raw, Sharded. Object: File, S3)
• Memory-safety & Race-free NBD Server implementation, thanks to Rust

DO NEVER USE THIS FOR PRODUCTION

Do not use this for any data that you cannot afford to lose any moment. Expect data loss, corruption/bit rot, and every other possible storage disaster.

If you use alpha level software for your data, you might end up like we did previously => sheepdog/sheepdog#425

We're learning Rust, don't judge. Help instead.

• Successfully serve dummy empty file (filled with zeroes), enough to satisfy qemu-img info
• 0.0.1 Serve a raw image read-only from a file
  • consider mmap
• 0.0.2 Read/Write access
• 0.0.3 Storage Backend Abstraction
• 0.0.4 Sharded File Implementation. Shard image file into 4M chunks (my-image.{n}.chunk)
• 0.0.5 Object Storage Abstraction
• 0.0.6 S3 Object Storage
• 0.0.7 Cache Backend Implementation

• Known Issues (Fix before v0.1.0)
  • Fix panic at sudden disconnection
  • Fix panic at invalid export name
• Performance issues with Cache and S3 driver
  • Need multi-thread write workers (currently only a single extra thread)

• Retry Backend Implementation

• Trim Support

• Transmission Phase Refactor. Move to async/queue

  • currently all commands are executed serially, this severely effects performance

• Refactor NBDSession. Leverage Interior Mutability. (still learning Rust)

• Config/Argument syntax refactor. Consider having a config file as a last resort.

• Cache Storage refactor: split memory storage into a separate Object Storage driver

  • this will potentially allow using a file based cache layer (eg. on NVMe)

• Test Suite

  • Unit Tests
  • Integration Tests

Stretch goals

• Multi-volume support
• Multi-connection support
• Research Disconnect/Reconnection behavior
• Stateless Multi-server support
  • using Redis for state cache and coordination
• Encryption
• Sync and Async Mirrored backends
• Erasure coded backend
• HTTP backend
• Overlay (to overlay backends on top of each other, like using a snapshot)

cargo build

The executable binary is located at ./target/debug/nbd-rs.

Arguments:

[-e | --export EXPORT_NAME; DRIVER (raw, sharded); (cache)? CONN_STR]...
  Examples:
    -e disk0 raw cache:file:/test/
    -e disk1 sharded cache:file:/test/
    -e disk2 raw s3:http://username:password@${S3_HOST}/bucket
    -e disk4 sharded cache:s3:http://username:password@${S3_HOST}/bucket

Examples of export argument:

# Single Export (-e | --export), Raw, File, Log Level: DEBUG
RUST_LOG=debug ./target/debug/nbd-rs --export my_raw_export raw file:/export/path/

# Single Export, Sharded, S3, Log Level: TRACE
RUST_LOG=trace ./target/debug/nbd-rs -e my_raw_export sharded s3:/export/path/

# Single Export with Cache, Sharded, S3
./target/debug/nbd-rs -e my_sharded_export sharded cache:s3:http://username:password@${S3_HOST}/path

# Multiple Exports
./target/debug/nbd-rs -e my_raw_export raw file:/export/path/ -e my_sharded_export sharded s3:http://username:password@${S3_HOST}/path

NBD-rs will panic if no export has been specified.

docker build -t dkr.local/nbd-rs:dev .
docker run -it --rm -p 10809:10809 dkr.local/nbd-rs:dev --export ${EXPORT_NAME} raw file:/test/

See Run section for more information on arguments.

qemu-img info nbd:localhost:10809;exportname=${EXPORT_NAME}

Write local image to NBD:

# Connect to drive by reading
nbd-client -N ${IMAGE_NAME} localhost /dev/nbd0

# Write
dd if=${LOCAL_IMAGE} of=/dev/nbd0 bs=1M status=progress oflag=sync,direct

# Disconnect
nbd-client -d /dev/nbd0

Boot alpine with qemu:

qemu-system-x86_64   -enable-kvm   -machine q35,accel=kvm   -m 2048  -drive file=nbd:127.0.0.1:10809:exportname=${EXPORT_NAME},format=raw   -display gtk   -serial mon:stdio

VERY WELCOME! (Contributions to the contribution guide is also very welcome.)

Please see CONTRIBUTING.md

GPL-3.0

Copyright 2021, Rainlab Inc. Tokyo and nbd-rs contributors (please see commit history)