Conserve: a robust backup program
Conserve's guiding principles:
Robust: If one file is corrupted in storage or due to a bug in Conserve, or if the backup is interrupted, you can still restore what was written. (Conserve doesn't need a large transaction to complete for data to be accessible.)
Careful: Backup data files are never touched or altered after they're written, unless you choose to purge them.
When you need help now: Restoring a subset of a large backup is fast, because it doesn't require reading the whole backup.
Always making progress: Even if the backup process or its network connection is repeatedly killed, Conserve can quickly pick up where it left off and make forward progress.
Ready for today: The storage format is fast and reliable on on high-latency, limited-capability, unlimited-capacity, eventually-consistent cloud object storage.
Fast: Conserve exploits Rust's fearless concurrency to make full use of multiple cores and IO bandwidth. (In the current release there's still room to add more concurrency.)
Portable: Conserve is tested on Windows, Linux (x86 and ARM), and OS X.
Quick start guide
Conserve storage is within an archive directory created by
conserve init /backup/home.cons
conserve backup copies a source directory into a new version within the
archive. Conserve copies files, directories, and (on Unix) symlinks. If the
conserve backup command completes successfully (copying the whole source
tree), the backup is considered complete.
conserve backup /backup/home.cons ~
conserve versions lists the versions in an archive, whether or not the backup
is complete, the time at which the backup started, and the time taken to
complete it. Each version is identified by a name starting with
$ conserve versions /backup/home.cons b0000 complete 2016-11-19T07:30:09+11:00 71s b0001 incomplete 2016-11-20T06:26:46+11:00 b0002 incomplete 2016-11-20T06:30:45+11:00 b0003 complete 2016-11-20T06:42:13+11:00 286s b0004 complete 2016-12-01T07:08:48+11:00 84s b0005 complete 2016-12-18T02:43:59+11:00 4s
conserve ls shows all the files in a particular version. Like all commands
that read a band from an archive, it operates on the most recent by default, and
you can specify a different version using
-b. (You can also omit leading zeros
from the backup version.)
$ conserve ls -b b0 /backup/home.cons | less
conserve restore copies a version back out of an archive:
$ conserve restore /backup/home.cons /tmp/trial-restore
conserve validate checks the integrity of an archive:
$ conserve validate /backup/home.cons
--exclude GLOB option can be given to commands that operate on files,
/ at the start of the exclusion pattern anchors it to the top of the backup
tree (not the root of the filesystem.)
** recursively matches any number of
At the moment exclusion patterns must always start from the root, so you need
**/*.swp to exclude
.swp files anywhere in the tree.
The syntax is comes from the Rust globset crate.
To build Conserve you need Rust and a C compiler that can be used by Rust.
To install the most recent release from crates.io, run
cargo install conserve
To install from a git checkout, run
cargo install -f --path .
On nightly Rust only, you can enable a potential speed-up to the blake2 hashes with
cargo +nightly install -f --path . --features blake2_simd_asm
Conserve can reasonably be used for backups today: the format is stable, in my use it's reliable, and the basic features are complete.
Be aware that Conserve is developed as a part-time non-commercial project and there's no guarantee of support.
Some other limitations:
conserve diffexists, but is not yet very useful.
conserve purgecommand to trim the backup archive is not implemented, but the
b0123band directories can be deleted directly.
- Permissions and ownership are not stored.
Prior to 1.0, data formats may change on each minor version number change (0.x): you should restore using the same version that you used to make the backup.
Windows Defender and Windows Search Indexing can slow the system down severely when Conserve is making a backup. I recommend you exclude the backup directory from both systems.
Licence and non-warranty
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.