Markus Demleitner





Waived under CC-0

The GAVO Data Center Helper Suite (DaCHS) is a publishing infrastructure for the Virtual Observatory, including a flexible component for ingesting and mapping data, integrated metadata handling with a publishing registry, and support for many VO protocols and standards.

This is a re-rendering of the upstream DaCHS documentation.


All of this is very much work in progress. Users asking for elaboration are certainly good indicators of where need is greatest.

What to read when?

Obviously, you should start with the installation instructions (have a brief glance at them even if you install from Debian package). You should then probably read and work through the tutorial to get a feel for how DaCHS works. That’s about all there is to read sequentially.

When you get error messages you don’t understand, check the “Hints on common problems”. When you have some funky litte requirement the solution for which is not immediately obvious, try the “How do I” document. If what you want is not covered, ask the authors.

The reference is, well, the reference, and I’m afraid you’ll have to look up things in there fairly regularly. The good news is that there’s examples in the index to elements and attributes in the GAVO DC; these are essentially live, and as long as you’ve had a look at the reference, there’s nothing wrong with lavishly copying from there.

You can ignore the topic guides (booster grammars, preprocessing, anything else that might yet come) until you notice you need to read them.

Deployment Options

For Data Center Operators

For VO Data Providers

Library Documentation


To obtain the software (or parts of it), see


If you run a DaCHS server, please subscribe to the DaCHS-users mailing list. It is low volume (less than one mail a month), and you get to know when new releases come out. We’d also appreciate being able to alert our users in case a security hole should be discovered in the software (which has happened once in the past ten years).

If you have questions regarding DaCHS, we’d appreciate if you subscribed and sent your question to the DaCHS-support list (if all support requests went on the list, we’d expect a volume of about one mail per day, but let’s see). It has a public archive, and other users can profit from our (and your peers’) answers, which is why we prefer the list to questions sent directly to; these will of course still be answered.

Material related to DaCHS and the VO in general is also published now and then on GAVO’s blog

More interactive support may also be available via IRC, channel #gavo on You can also try mumble via


If you want or need to reference DaCHS, I suppose you should be citing 2014A&C…..7…27D. If you can’t bring yourself to boosting an Elsevier journal’s impact factor, you have my sympathies, and you’re welcome to cite the (less informative, more difficult for bibstyles) ASCL entry at 2018ascl.soft04005D.