[DRBD-user] drbd peer outdater exit codes [drbd ocf floating peers not working. don't try]

Raoul Bhatia [IPAX] r.bhatia at ipax.at
Fri Sep 12 13:53:07 CEST 2008

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.

Lars Ellenberg wrote:
> don't do that.
> won't work with any handlers.
> for the "floating peer" stuff to work in practice,
> we'd need much more work in the user land tools.
> while a neat idea in theory,
> it does not work out in practice.
> it even uses an undocumented "hack",
> namely setting the "__DRBD_NODE__" environment variable,
> which was introduced solely to make it more easy for me
> to "sanity check" drbd config files sent to me to comment on,
> using the "dump" and "-d up" and similar commands.
> it was never intended to be actually used.

ok, i never realized that as it was explicitly mentioned in
the linux-ha documentation.

> so the whole "floating peer" stuff is a hack in itself.
> does anybody out there really use it?

well, if you have not got a dedicated storage subsystem with
2/3 nodes but rely on e.g. 2 nodes out of 5 doing the mirroring
and offering files via nfs, or
  you do not care where service x is started but need the drbd device
for it to function properly, or
  you want to have some "hot-spare-nodes" for your cluster, it sounds
like "a neat idea" :)

but i've only used it in cases where i too would be able to use the
actual hostname(s).

> it might be possible to get this hack sort of working
> by adding more hacks. like telling the kernel which
> "nodename" to fake when calling the user space helpers.
> but I don't think that would be a good idea.

correct me if i am wrong but saving the node's alias during drbdadm
attach/up/etc. shouldn't be that bad, because it already has been used
to find the right configuration from the drbd.conf file anyway.

DI (FH) Raoul Bhatia M.Sc.          email.          r.bhatia at ipax.at
Technischer Leiter

IPAX - Aloy Bhatia Hava OEG         web.          http://www.ipax.at
Barawitzkagasse 10/2/2/11           email.            office at ipax.at
1190 Wien                           tel.               +43 1 3670030
FN 277995t HG Wien                  fax.            +43 1 3670030 15

More information about the drbd-user mailing list