I have a Z87 motherboard with a RAID originally set up as follows:
A few months back one of the 500GB drives failed and I've rebuilt the array with 2x1TB HDD - however, I haven't increased the volume size at the time.
I see that the Smart Response Technology desktop app offers me an option to increase the size of the RAID 1 array to fill the entire drive capacity and would like to do so - however, the help document states something that gave me pause:
If you perform a driver upgrade or downgrade while data migration is in progress and then restart your computer, the driver will not be able to recognize the volume or data on it. If you are migrating your system volume, you will not be able to restart your system because the operating system cannot load. If you are migrating a data volume, you will have to reverse that last performed driver update, and then restartyour computer to return to a normal state. Refer to Troubleshooting Errors for more information.
What concerns me is the second part: "If you are migrating your system volume, you will not be able to restart your system because the operating system cannot load".
Does it refer only to a situation where a system volume is migrated during a driver update, or does it refer to any attempt to increase the size of a system volume?
No, it is saying that a reboot during the migration process could result in corruption and/or data loss. Don't do it. Don't let Windows do it either. Best to disconnect the Ethernet cable and/or disable wireless while the migration is going on.
Also, before doing any of this, please, please, please make a backup of your data!