How can we setup the primary node, restart the iSCSI Failover and make this node active again?

Article ID: 1053

Last updated: 14 Sep, 2011

Symptom:

Not only data but also the whole configuration of the primary node is lost because of e.g. a broken RAID controller.

Problem:

Currently it’s not possible to add a “clean” DSS node and automatically restore the whole configuration. Most probably it will be possible in the further but for now we can use this description as a workaround.

Restoring the data and settings on the primary node that was used in the iSCSI Failover is quite complicated and a bit tricky, that’s why we strongly recommend to make a backup of
all the data that you have on the secondary node, before proceeding with the
recovery process described bellow.

Unfortunately it’s not possible to restore the configuration and data on the primary node without stopping the the iSCSI Failover functionality on the secondary node. If there
are any clients connected to the shares/iSCSI targets via the virtual IP’s used in the iSCSI Failover configuration, then they will lose the connection.

Solution:

To make the description shorter we will use the following abbreviations:

PN - primary node

SN - secondary node

LV - logical volume

Let’s start with the restoring process:

1). Repair/replace the faulty hardware and reinstall the DSS on the main node (PN). Make sure that the same DSS V6 builds are installed on both nodes, otherwise it won’t be possible to start the iSCSI Failover

2). Reconfigure the network and administrator settings on the PN
3). On the PN recreate the volume group and logical volumes. (remember that the LVs,
that you want to replicate and use in the iSCSI Failover need to have the same size on both
DSSes/nodes and the “use volume replication” need to be set)
4). Stop the the iSCSI Failover on the SN
5). Remove replication tasks with “reverse” in their name from the SN
6). On the SN change the LV’s volume replication mode to destination
7). On the PN set the LV’s volume replication mode to source
8). Create new replication tasks on the PN (you will see reverse tasks
automatically created on the SN)
9). On the PN set the volume replication mode back to destination
10). On the SN set the volume replication mode back to source
11). Run reverse replication tasks on the SN (in order to restore the data back
to the LV’s on the PN)
12). If you can’t start the replication process, go back to the SN. In the volume
replication mode, use “clear metadata”. When it’s applied, run again the
replication tasks on the SN
13). after the replication process is finished, stop the reverse replication tasks
on the SN
14). set the the volume replication mode to destination on the SN
15). set the the volume replication mode to source on the PN
16). run the replication tasks on the PN
17). continue with the iSCSI Failover configuration