[DRBD-user] LINSTOR Satellite DRBD version check

[Robert Altnoeder]

One of the next releases of LINSTOR will add a check for a supported
DRBD installation to the Satellite's startup routines.

The satellite will automatically shutdown if it can not verify that DRBD
9 is installed (that includes cases where the system has a working DRBD
installation, but it is DRBD 8.4.x, 8.3.x or some even older version of
DRBD that is not supported by LINSTOR).

The message is quite obvious:

[Main] ERROR LINSTOR/Satellite - Satellite startup failed, unable to
verify the presence of a supported DRBD installation [Report number
5C0134C0-FCE79-000000]

[Thread-14] INFO LINSTOR/Satellite - Shutdown in progress
[Thread-14] INFO LINSTOR/Satellite - Shutdown complete

The error report is even more detailed and also contains information on
supported versions of DRBD.

If you actually intend to run the Satellite without any DRBD
installation at all (this affects mostly future versions that will
manage other types of storage as well), the check can be turned off with
the '--skip-drbd-check' command line option.

br,
Robert

[Roland Kammerer]

Post by Robert Altnoeder
One of the next releases of LINSTOR will add a check for a supported
DRBD installation to the Satellite's startup routines.
If you actually intend to run the Satellite without any DRBD
installation at all (this affects mostly future versions that will
manage other types of storage as well), the check can be turned off with
the '--skip-drbd-check' command line option.

I don't think that is a good idea. Nobody starts up the satellite
manually, it is started by systemd (or whatever flavor one prefers). And
micro-packaging a linstor-satellite-drbd/linstor-satellite-nodrbd is a
bad idea.

The controller has all the knowledge whether a given satellite needs
DRBD or not. And depending on that, the controller should initiate that
check.

Regards, rck

[Robert Altnoeder]

Post by Roland Kammerer
I don't think that is a good idea. Nobody starts up the satellite
manually, it is started by systemd (or whatever flavor one prefers). And
micro-packaging a linstor-satellite-drbd/linstor-satellite-nodrbd is a
bad idea.

We'll figure out what alternatives there are and what the pros and cons are.

We could presumably run the check before attempting to deploy the first
resource that requires DRBD, and if the check failed, repeat the check
every time the DeviceManager retries the resource creation. Once the
check completes, it would not normally run again until the satellite is
restarted.

Another possibility would be to run the check whenever a DRBD-related
operation failed.

What I would like to avoid is running the check every time the
DeviceManager service modifies a resource, because since the check runs
an external command, it can potentially introduce high latency.

Post by Roland Kammerer
The controller has all the knowledge whether a given satellite needs
DRBD or not. And depending on that, the controller should initiate that
check.

The Satellite should be able to do that autonomously on the Satellite
side with the information received from the Controller (storage pools,
specifically), that would avoid any additional processing load on the
Controller when it connects to Satellites.

br,
Robert