[DRBD-user] Disconnect primary if secondary is too slow to respond

Moti Levy moti at 101tech.net
Mon Sep 9 18:18:56 CEST 2013

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

I am looking for some recommendations for a specific scenario:

Secondary DRBD node IO subsystem is busy and disk operations become
extremely slow. The secondary is still responding, but very slowly (
for example, if you have a raid device and one drive is being rebuilt,
or if you are on amazon and their EBS volumes are degraded ).

In this case, DRBD's queues ( application pending, pending ) start to
build up, and at some point will block ay application from writing to
the device.

At this point if I set the primary to standalone ( or disconnect the
secondary ) the applications will regain write access.

I am interested in having this done automatically, is there a way to
let DRBD know if application_pending becomes a write blocking issue to
disconnect and switch to standalone ?


More information about the drbd-user mailing list