Hello,  By default when you add a new device to ScaleIO, it will automatically initiate a rebalance of data on to the new disk/s. You can disable the rebalance feature by using the ScaleIO GUI for the specific Storage pool that the device is being added to. Open ScaleIO GUI > select backend tab > sort by Storage pools > right click the Storage pool > select "Enable/Disable Rebuild/Rebalance"  Hope this helps.
I need to add one disk per node (5 nodes) and add this disk to SDS. There is no information about addition of new disk in existing SDS, only about error disk replacement.  When i "add new device" Is there a chance to start rebalance/rebuild when i add new device to SDS? I strognly don't want that to happen (first, add disks to all servers, then perform rebalancing)  Hypervisor - VMware ScaleIO version - v2.0-13000.211
Addition of new disk in existing SDS