https://github.com/spullara/nbd

NDB server
https://github.com/spullara/nbd

foundationdb java nbd nbd-client storage-service volume

Last synced: 2 months ago
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NDB server

• Host: GitHub
• URL: https://github.com/spullara/nbd
• Owner: spullara
• License: other
• Created: 2014-11-02T21:06:50.000Z (about 10 years ago)
• Default Branch: master
• Last Pushed: 2024-05-31T20:07:34.000Z (8 months ago)
• Last Synced: 2024-10-14T19:35:27.845Z (3 months ago)
• Topics: foundationdb, java, nbd, nbd-client, storage-service, volume
• Language: Java
• Size: 42 KB
• Stars: 64
• Watchers: 8
• Forks: 9
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-foundationdb - Java NBD server

README

        
License

=======

Copyright 2018 Sam Pullara

Licensed under the Apache License, Version 2.0 (the "License");

you may not use this file except in compliance with the License.

You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software

distributed under the License is distributed on an "AS IS" BASIS,

WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

See the License for the specific language governing permissions and

limitations under the License.

Network Block Device

====================

The nbd-client on Linux allows you to mount a remote server implementing the NBD protocol

as a local block device. This NBDServer exports volumes whose data is stored in

FoundationDB. This gives you a highly scalable, high performance, reliable block device that

you can then format and put a filesystem on it.

The NBDCLI command allows you to create new volume, list the volumes you have in your system,

delete a volume or snapshot a current volume to another volume.

HOWTO

=====

Bring up FoundationDB and then run the NBDServer. It will be listening on the default 10809 port.

```bash

java -jar nbdcli.jar server

```

Create a new 1G volume:

```bash

java -jar nbdcli.jar create -n [volume name] -s 1G 

```

On a Linux host, install ndb, create the block device, format it and mount it:

```bash

sudo apt-get update && apt-get install nbd

sudo modprobe nbd

sudo nbd-client -N [volume name] [host] /dev/nbd0

sudo mkfs.xfs /dev/nbd0

mkdir tmp

sudo mount /dev/nbd0 tmp

```

You may need to change the ownership on that directory to access it but you can now save files

there and they will be backed by FoundationDB. Each volume can only be shared to a single nbd client

at a time. 

Under the covers

================

Each volume is a sparse array of bytes (FDBArray) stored in FoundationDB across many rows in the database. In addition

each volume can have a parent whose sparse array shows through where the child volume hasn't written yet. Here is the

interface that we implement:

```java

public interface Storage {

  void connect();

  void disconnect();

  CompletableFuture read(byte[] buffer, long offset);

  CompletableFuture write(byte[] buffer, long offset);

  CompletableFuture flush();

  long size();

  long usage();

}

```