Afio archiver home page
This is the home page for the afio archiver program for Linux/UNIX.
Afio makes cpio-format archives. It deals somewhat gracefully with
input data corruption, supports multi-volume archives during
interactive operation, and can make compressed archives that are much
safer than compressed tar or cpio archives. Afio is best used as an
`archive engine' in a backup script.
The latest version is 2.5.2, released in 2018.
This announce message describes the major
Afio is free/open source software. As an open source project, it is somewhat
peculiar because it is over 30 years old.
There is no guarantee that these two methods will get you exactly the
same version of afio. In general, the Debian package maintainers and
me as the upstream project maintainer try to keep things in sync, but
we all have limited time. If you run
- If your Linux is Debian or Debian-based, you can try
sudo apt-get install afio
- Or you can compile afio from source.
The latest source release is at
http://members.chello.nl/~k.holtman/afio-2.5.2.tgz. See the INSTALLATION file in the source release for instructions. If you are impatient, pasting this to a terminal may work:
tar zxf afio-2.5.2.tgz
sudo make install
afio without any
command line arguments it will print its version number.
Reporting problems, questions, bugs, submitting patches, etc
There are many options.
- Send me an e-mail at
Koen.Holtman@ieee.org with the
word afio somewhere in the subject line.
- Use the issue
submission or patch submission system attached to the Github repository.
- If you are using afio via Debian or are reporting an issue specific to the Debian package, use the Debian bug reporting page.
Afio is now in a 'maintenance only' mode, with several years between
formal releases. 'Maintenance only' means that I will be happy to
answer questions, to handle bug and problem reports, and to
incorporate patches that fix bugs, portabiliy problems, and security
issues. However, it is very unlikely that I will work on adding major
new features, even if the feature request comes with a patch file
implementing the feature.
The main concern that drives my maintenance policy is to avoid
creating new bugs that would cause the backup process to silently
fail. Because of this concern, I do a lot of manual reviewing and
testing for every patch I receive. I have concluded that I simply do
not have the time (and interest level) anymore to do this for patches
adding new features. My interest has declined because since about
2005, hard drives have become so cheap that making fault tolerant
compressed archive files for writing to tapes of floppy disks, as afio
can do, has become less and less relevant to the needs of average
Linux user. I make my personal system backups using rsync on a
detachable hard drive.
When to use Afio
Selecting a backup solution for Linux can be a problem. There are too
many software solutions. Some of them are not maintained at all
anymore. Many of them (including afio) are not maintained very
My recommendation depends on what you want to do:
- You want to package some files together to put on a web
site or in an e-mail.
In this case, use a well-known archiver
that everybody has installed by default, like tar or zip.
- You want to make a backup, and you have a removable or remote
hard drive/flash drive with plenty of space.
In this case, copy
the entire filesystem tree you want to back up.
You can use a file system copying tool like rsync,
or a GUI tool that incorporates rsync.
- You want to make a backup to a compressed archive to save
Typically this happens when backing up to
CD/DVD/Blu-ray disks or tape. In this case:
- Do not use
tar cvz or any other archiver
that compresses the whole archive: if there is even a single byte
error when reading back the archive you will loose all files
that are located past the byte error.
- Do use afio with its compression option, or a backup tool
that uses afio to make compressed archives, like mondorescue.
You will get compressed archives that are fault tolerant: if there is
a single byte error you will only loose one or two files.
Afio is also sometimes used together with pgp or gpg to make fault
tolerant encrypted archives. Some people use it to archive unusual
filesystems that have 100.000s of hard links or that have
filenames with '\n' characters inside.
History and License
The original version of afio was written by Mark Brukhartz in 1985.
it to the comp.sources.unix USENET newsgroup in 1987. This newsgroup
was an early distribution mechanism for free UNIX software. Since
1987, 100s of people have contributed to afio, and the afio code size
has grown by a factor of 4. In 1992, the first Linux port of afio was
uploaded to Sunsite, an early Linux FTP site. Koen Holtman became the
afio maintainer in 1994 and has been so ever since. Afio attracted
significant developer mindshare in the period 1992-2003 because it was
the only open source archiver offering fault tolerant compression,
which was important at the time for people making backups to floppies,
tape drives, and later CDs. After 2003, development activity on afio
slowed down a lot. This was partly because of software maturity, and
partly because the lower cost of storage made compression less of an
Afio has always been available for free. However, the original afio
license written in 1985 (see
pre-dates modern open source licenses written with the help of actual
lawyers. Around 2008, some people started to see this as a serious
problem. There are two ways to look at the license:
If reading about this kind of license stuff is your idea of fun,
- The afio license is free. It was written to support an open
source style of development. It gives users, developers, and
distributors many freedoms.
- The afio license is non-free. It is legally too vague
according to modern open source licensing standards. This vagueness
makes it inappropriate as an open source license. There are worries
that the vaguenes may restrict the freedoms of some distributors. As
there are hundreds of copyright holders involved, it is not possible
to upgrade the license to something better.
Koen Holtman. Last updated November 2018.