diff --git a/xml/depl_docupdates.xml b/xml/depl_docupdates.xml index bea0e9ca5..0fa5aaed9 100644 --- a/xml/depl_docupdates.xml +++ b/xml/depl_docupdates.xml @@ -474,6 +474,12 @@ (). + + + Added + (). + + Provided additional information on bonding modes at - + + + Recovering From an Unresolvable DRBD Split Brain Situation + + + Although policies to automatically resolve a DRBD split brain situations + exist, there are situations which require to be resolved manually. Such a + situation is indicated by a Kernel message like: + + kernel: block drbd0: Split-Brain detected, dropping connection! + + To resolve the split brain you need to choose a node which data + modifications will be discarded. These modifications will be replaced by + the data from the healthy node and will not be recoverable, + so make sure to choose the right node. If in doubt, make a backup of the + node before starting the recovery process. Proceed as follows: + + + + + Put the cluster in maintenance mode: + + crm configure property maintenance-mode=true + + + + If the chosen node is in primary role, stop all services using this + ressource and switch it to secondary role. Skip thios step, if the + already is in secondary role. + + drbdadm secondary RESSOURCE + + To check if a node is in primary role, see the output of + systemctl status drbd. + + + + + If the node is in state WFConnection disconnect + the ressource: + + drbdadm disconnect RESSOURCE + + To check if a node is in state WFConnection, + see the output of systemctl status drbd. + + + + + Discard all modifications on the chosen node. This step is + irreversible, the modifications on the chosen node will be lost! + + drbdadm -- --discard-my-data connect RESSOURCE + + + + If the other (healthy) node is in state + WFConnection, synchronization to the chosen node + will start automatically. If not, reconnect the healthy node to start + the synchronization. + + drbdadm connect RESSOURCE + + During the synchronization all data modifications on the chosen node + will be overwritten with the data from the healthy node. + + + + + Reset the cluster to normal mode when the synchronization has + finished: + + crm configure property maintenance-mode=false + + +