[DRBD-user] drbd source "add-on" vs "built-in" ?

Dan Gahlinger dgahling at gmail.com
Sun Feb 11 17:19:25 CET 2007

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


I have a question which perhaps many people might have,

Is there any performance or reliability difference between using the
"add-on" drbd source download

or using the "built-in" kernel modules in Suse such as
"kmp-bigsmp" and so forth?

I noticed in Suse 10.2 they not only include the RPM of DRBD,
but they also include two other packages which are NOT included if you
just use the source. they are "kmp-default" and "kmp-bigsmp" (there is
a third, but I don't use it, it is "kmp-xen").

I was just wondering about reliability or stability differences between them?
I'm thinking the built-in would be preferable. Why? because it got me
to thinking about booting.

When the system boots, one of the first things it does is mount the
filesystems (fstab),
but the drbd volume is an EVMS which means it needs drbd running in
order to mount it.
But it seems to become a catch-22.

You can't mount the volume without drbd running, and you cant run the
drbd "service' (add-on) without mounting the filesystem. Which is
where the kernel modules, and specialized kernels come in, they'd get
loaded with the kernel.

part two is - as a "built-in" it's part of the kernel, specially
compiled, which means its a bit "lower level" than just a service.

or am I completely off-track here?



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