Skip to content

Latest commit

 

History

History
100 lines (63 loc) · 4.19 KB

ADDENDUM.md

File metadata and controls

100 lines (63 loc) · 4.19 KB

nvme-stas Addendum

D-Bus Interface

Both stafd and stacd expose D-Bus interfaces that allow external programs—including stafctl and stacctl—to communicate with the daemons. Third-party applications can also integrate with nvme-stas via these APIs. For example, a graphical utility could display available discovery controllers or present discovery log pages in a visual format.

D-Bus Service Names

Component D-Bus Service Name
stafd org.nvmexpress.staf.conf
stacd org.nvmexpress.stac.conf

Troubleshooting Service Discovery with Avahi

stafd can automatically discover and connect to Discovery Controllers using mDNS/DNS-SD via the Avahi daemon. Controllers advertising the _nvme-disc._tcp service type will be detected by Avahi and forwarded to stafd.

Not Receiving mDNS Packets?

If stafd is not detecting any discovery controllers via Avahi, the firewall may be filtering mDNS packets. If you know that Discovery Controllers are actively advertising, check whether Avahi is receiving the packets:

avahi-browse -t -r _nvme-disc._tcp

If no services appear, verify that your firewall allows UDP multicast on port 5353 (mDNS).

Why Avahi Fails on Some Interfaces

Linux limits the number of multicast group memberships per socket. The default (igmp_max_memberships) is 20. Avahi joins one multicast group per network interface—whether physical or logical. For example, adding multiple VLANs increases the number of logical interfaces.

If the total interface count exceeds this limit, Avahi will be unable to listen on all of them, causing incomplete service discovery.

To increase the limit, update the igmp_max_memberships sysctl parameter. Useful references:

Testing

For information on executing or writing tests, refer to: TESTING.md

Make Wrappers

To streamline Meson workflows, several operations are wrapped in convenient make targets:

Make Target Description
make Builds the project. Automatically runs .configure with default parameters if necessary.
make install Installs the software (requires root privileges).
make uninstall Removes installed files (requires root privileges).
make test Executes the unit test suite.
make clean Removes build artifacts but preserves the Meson configuration in .build.
make purge Removes all build artifacts, including the .build directory.
make update-subprojects Updates subprojects such as nvme-cli.
make check-format Verifies coding style compliance.

Generating Documentation

nvme-stas uses external tools to generate man pages and HTML documentation:

  • xsltproc — Converts DocBook XML into man and HTML formats.
  • gdbus-codegen — Converts D-Bus IDL files into DocBook XML.

Document Generation Dependencies

Install the following packages depending on your distribution:

Debian-based systems (e.g., Ubuntu 20.04+, Debian 11+):

sudo apt-get install -y docbook-xml docbook-xsl xsltproc libglib2.0-dev

RPM-based systems (e.g., Fedora 34+, RHEL 9+, SLES 15+):

sudo dnf install -y docbook-style-xsl libxslt glib2-devel

Building Man and HTML Pages

Documentation generation is disabled by default. To enable it, reconfigure Meson with the appropriate flags. If necessary, purge any previous build configuration:

make purge
./configure -Dman=true -Dhtml=true
make