RZBackup

http://rzbackup.com

James Pharaoh james@pharaoh.uk

This is a partial Rust clone of ZBackup, along with some unique features of its own.

This project is free software and available under the [Apache 2.0 licence] (https://www.apache.org/licenses/LICENSE-2.0).

Binaries for ubuntu are available can be downloaded [here] (https://dist.wellbehavedsoftware.com/rzbackup/).

Online documentation is automatically generated by [docs.rs] (https://docs.rs/rzbackup/).

List of features

• Rust library for access to ZBackup repositories
• Supports encrypted and non encrypted formats
• Multi-threaded restore and configurable, multi-tier chunk cache
• Client/server utilities to efficiently restore multiple backups with a shared chunk cache
• RandomAccess implements Read and Seek to provide efficient random access for rust applications
• Balance tool to redistribute data in index and bundle files, typically useful to obtain a smaller number of consistently-sized files
• Thorough garbage collection tool to clean up indexes and chunks which are no longer in use
• Command line decrypt utility, mostly useful for debugging

Notable missing features

• No facility to create backups, these must be performed with the original ZBackup tool
• Verification of backup checksums is not performed

Library usage

In cargo.toml:

toml [dependencies] rzbackup = '3.0'

Example code, for demonstration (won't compile):

```rust extern crate rzbackup;

use rzbackup::Repository; use rzbackup::RandomAccess;

fn main () {

let mut repository =
    Repository::open (
        "/path/to/repository",
        Some ("/path/to/password/file"));

repository.restore (
    "/backup-name",
    output_stream ());

let mut random_access =
    RandomAccess::new (
        repository,
        "/backup-name");

do_something_with_random_access (
    random_access);

} ```

Command usage

Restore

The restore command is able to perform a one-off restore. It is basically equivalent to ZBackup's own restore command.

sh rzbackup-restore REPOSITORY PASSWORD-FILE BACKUP > OUTPUT-FILE rzbackup-restore REPOSITORY '' BACKUP > OUTPUT-FILE

Server

The server process listens for client connections and streams backups over a socket. It has a large cache and so will be more efficient than running separate restore processes for backed up data with lots of shared deduplicated content.

sh rzbackup-server LISTEN-ADDRESS:PORT REPOSITORY [PASSWORD-FILE]

Client

The client connects to the server and streams a backup to standard output. It can also tell the server to reload its indexes, which will be necessary if new backups have been made.

sh rzbackup-client reindex SERVER-ADDRESS:PORT rzbackup-client restore SERVER-ADDRESS:PORT BACKUP-NAME > OUTPUT-FILE

Convert

The convert tool makes low-level changes to the repository. It is able to balance both index and bundle files, changing the number of entries they contain. It can also perform garbage collection, removing index entries and chunk data which is no longer referenced by any backups.

```sh rzbackup-convert gc-indexes \ --repository REPOSITORY \ --password-file PASSWORD-FILE

rzbackup-convert gc-bundles \ --repository REPOSITORY \ --password-file PASSWORD-FILE

rzbackup-convert balance-bundles \ --repository REPOSITORY \ --password-file PASSWORD-FILE

rzbackup-convert balance-indexes \ --repository REPOSITORY \ --password-file PASSWORD-FILE ```

A typical use case would be to balance indexes and bundles regularly, and to perform garbage collection after deleting backups. The commands should be run in the order shown above, in order to leave the repository in an optimal state.

Please be aware that these commands are designed to be used with a repository which is not being read or written to by other tasks, although they do try to accommodate such access.

These tools may leave the repository in an inconsistent state if they are interrupted, although they do attempt to reduce the window for this to happen as much as possible. The balance-bundles tool will almost always leave multiple index entries if interrupted, although this should be relatively easy to repair.

Decrypt

This is mostly useful for debugging. It allows you to show the decrypted contents of any backup, index or bundle file in a ZBackup repository.

sh rzbackup-decrypt REPOSITORY PASSWORD-FILE ENCRYPTED-FILE > OUTPUT-FILE