[ClusterLabs] One volume is trimmable but the other is not?

[Eric Robinson]

> > I sent this to the drbd list too, but it’s possible that someone here
> > may know.
> >
> >
> >
> > This is a WEIRD one.
> >
> >
> >
> > Why would one drbd volume be trimmable and the other one not?
> >
> 
> iirc drbd stores some of the config in the meta-data as well - like e.g. some
> block-size I remember in particular - and that doesn't just depend on the
> content of the current config-files but as well on the history (like already
> connected and to whom).
> Don't know if that helps in particular - just saying taking a look at differences
> on the replication-partners might be worth while.
> 
> I know that it shows the maximum discard block-size 0 on one of the drbds
> but that might be a configuration passed down by the lvm layer as well.
> (provisioning_mode?) So searching for differences in the volume-groups or
> volumes might make sense as well.
> 
> Regards,
> Klaus

Thanks for your reply, Klaus. However, I don't think it's possible that anything could be getting "passed down" from LVM because the drbd devices are built directly on top of the raid arrays, with no LVM layer between...

{
        on ha11a {
                device /dev/drbd1;
                disk /dev/md3;
                address 198.51.100.65:7789;
                meta-disk internal;
        }

        on ha11b {
                device /dev/drbd1;
                disk /dev/md3;
                address 198.51.100.66:7789;
        meta-disk internal;
        }
}

--Eric