Best Practice for restoring a degraded Active-Active Cluster on a new VG/Host

We tried to figure out a way to restore a degraded A-A Cluster without shutting the cluster down (or at least with minimum downtime). We want to use the A-A Cluster as a kind of RAID 10 between two servers to avoid double redundancy (and double costs for the SSDs). For this and for better performance we use RAID 0 configurations inside the single Server which mirrors with the second server in a A-A Cluster. We are looking for the same kind of "plug and play" comfort and the easy handling that you have with a "normal" hardware disk-RAID 10 or 5, which means that you can drag the broken disk out and replace it with a new one without shutting the RAID down.

If this happens with the RAID 0 inside one of the A-A partners (which will be more likely with a RAID 0) or if one of the servers gets totally broken and needed to be replaced we have to restore the complete configuration to the exact same status it had before this accident and re sync the two servers again. Is there a best practice how to do this ?

I have seen instances where once the raid is rebuilt(clean array), the system can be joined to the cluster by simply restoring a backed up config.
But if the idea is to try and actually cluster the array across nodes, this will not work. To do this you will likely need a cluster file system, or deduplication.

The idea was just to rebuild an Active-Active Open-E System when one of the servers has to be replaced. This should be done at best without stopping the degraded Failover state. We are running nearly 100 VMs on these SANs and it took an our to restart them.

The Server cannot simply rejoined because it had new disks with empty space. The disk configuration is not saved with the Open-E config.....

We are aware of this problem and we sent this request to PM that there is no simple way to add a "new" server to running cluster.

If your boot medium was not damaged and you saved your configuration, you can recreate your VG, restore LVM under console and then restore your configuration using webGUI. This should allow you to add this server back to the cluster.

You can also set MPIO with physical IP for the time of reconfiguration of Failover but those are only workarounds.

Thanks for this information. We have had some similar steps in mind to restore this setting to a new server. Did you mean by "recreate your VG" the configuration within the RAID controller software or within Open-E ? If you restore the LVM with the console did this recreate the VG structure from Open-E too ? Do we have to restore the configuration with webGui only or also the setup (whats the difference by the way....) ? Did this also restore the Failover setup ? How do we sync the contend of the the mirrored VGs back to the new server (Failback) ? Do we have to setup new replication task with switched source <> destinations or can we use the existing ones ? Might be a good idea for Mr. Bak to do a failover webinar.....

Setup settings is kept on boot medium. It contains everything that is set in SETUP tab in DSS Web GUI.
Configuration settings are kept on system volume (volume group) and contains everything that is set in CONFIGURATION tab.

LVM restore tool allows you to restore volume group configuration from save files. There are 3 save files kept on boot medium, rotated and generated on reboots and each volume group change.

Currently it is not possible to join clear node to failover without stopping it.
This functionality is added to product road map and hopefully will be implemented soon.