SlapOS is a decentralized Cloud Computing technology that can automate the deployment and configuration of applications in a heterogeneous environment.


The goal of this document is to provide a list of Frequently Asked Questions, and their answers.

"How To" questions

Q: How can I quickly have a working ERP5/KVM/wordpress/whatever with SlapOS on my node?

A: Follow the official documentation at

Q: How to create a "vifib" or "slapos" account?

A: VIFIB has been renamed quite recently. You can find "vifib" written sometimes in the SlapOS Node, but it means "".

To create a account, just go to, click "login" then "join".

Q: How to delete a SlapOS Node (a.k.a computer or server) from

A: go to "My Space", "My Servers", click on your Node, then "Update Allocation Scope", then change it to read "Closed / Closed forever".

Q: How to reset a SlapOS service/instance?

A: Just destroy your current service on SlapOS Master, then request a new one.

Q: How to create an IPv4 frontend for my SlapOS instance?

A: Read the different examples available in the end of .

Note that you should have a configured SlapOS Client. Click here for the tutorial : Your client slapos.cfg should be up to date compared to

Q: How to contribute to Buildout?

A: Follow this link to read the answer:

Q: You made something wrong, how to tell SlapOS team?

A: Thanks for reporting this lurking bug on the SlapOS forum, we'll take care of it.

Q: How to know that SlapOS Node is correctly installed?

A: You can run two commands that are run automatically, just to be sure that they don't throw any error:

# slapos node format --now -v
# slapos node instance

Technical problems

I am having a BadStatusLine error, what to do?

A: If, when running slapgrid, you have an error like this one:

httplib.BadStatusLine: ''

It means that the server dropped the connection. It is likely that if you try again after a few seconds, it will work correctly.

Q: I am having a "Couldn't connect to the server" error

A: This error is like:

socket.error: Couldn't connect to the server. Please double check given master-url argument, and make sure that IPv6 is enabled on your machine and that the server is available. The original error was:_ssl.c:488: The handshake operation timed out

It means that SlapOS failed to correctly connect to the server. To understand the problem, you need to read the last part of the error.

Here it is "The handshake operation timed out". It means that the server was to slow/busy to answer. Just try again in a few minutes.

Q: I am having a "Couldn't authenticate computer" error

A: This error is like:

Couldn't authenticate computer. Please check that certificate and key exist and are valid. [Errno 336265225] _ssl.c:351: error:140B0009:SSL routines:SSL_CTX_use_PrivateKey_file:PEM lib

It means that the SlapOS Node could not authenticate itself to the server. To know what is happening, you should read the last part of the error.

Here it is "PEM lib". This is the ugly way of OpenSSL to say that it can't read/access the Node certificate defined in /etc/opt/slapos/slapos.cfg.
  • Does the two files (certificate and key) exist and are in the right location?
  • Is the content of the two files correct?
  • Haven't you inverted the two files?
  • Is there any permission error?
Q: I lost network connectivity while running slapgrid, what should I do?

A: When you are online again, with IPv6 connectivity, you just should run slapgrid (or let it be run again by cron). It should continue its work if any. If your network configuration is complex, you should check if it corresponds to tutorials pages (is the bridge okay?).

Q: Why my instances keeps being in "Looking for free partition" state after I requested it?
Several things can happen here :
  • You requested an instance of Software Release that is not available (not installed or no place left) in any node you have access to
  • You requested an instance of Software Release on a specific computer, but this computer can't accept this instance (Software Release not installed or no place let)
  • SlapOS Master is broken. It can happen, but don't bet on this option. Before reporting bug, check the first two options.
Q: The directory: 'XXX' to be used as a download cache doesn't exist.

A: Error is like:

Error: The directory:
to be used as a download cache doesn't exist.

Make sure that the tmp directory is accessible to the "slapsoft" user. Particularly, we've seen configurations where $TMPDIR was set to /root/tmp. Here, obviously, /root is not accessible to the "slapsoft" user, so buildout, run as slapsoft, miserably failed to create a directory there.

Q: How can I upgrade a deployed instance?

1/ Let's say we have a SlapOS Node with a Software Release installed, and a deployed instance named "my instance" of it. 2/ Then, the Software Release is released, let's say for an important security fix. The question is: how to upgrade my existing instance to the new Software Release to benefit the security fixes?

  • Install (= supply) the new Software Release in the machine (here,

  • Tell SlapOS to change your existing instance from the old Software Release to the new Software Release. It is currently only possible from the command line, configured with your account (see documentation to configure it):

    slapos request "my instance"

Then, slapos will change the links in "my instance" from the old Software Release to the new one.

Beware : currently, the new Software Release has to be backward compatible with the old one.

Q: I am using a Facebook/Twiter/Persona account, and "slapos node register" doesn't accept my password

A: This is a known bug of the beta version of SlapOS. It is solved in SlapOS 1.0.

Q: While installing KVM using nbd parameters, why do I get "Error While Instantiating" ?

A: This is a known issue and you should be able to reconnect after sometime.

Software specific problems

Q: Why do my mysql /mariadb instances die right after starting ?

A: It's a mysql/mariadb bug reported at On the dedicated USB key, we solve it like this: Our fix is based on

Q: Why do my ERP5 hang?

A: A possible source of problem is that the IPv4 of MariabDB changed. This bug is not yet well understood. You can compare, in /opt/slapos directory, your slapos.xml with backups in, and if needed, replace slapos.xml by one of its backup, then reboot.