[quote=“Paul, post:2, topic:143842”]
if you really do need the space, you might be able to use dashboard tools/settings, to untick the DDR mode, (in case this triggers any rebuild with flashing lights, please allow it plenty of time to finish, possibly upto a day per 1TB of data that you have, though usually enabling ddr will trigger a rebuild - i havent switched from ddr to sdr myself, and it might be best to check a bit more about whether there is a 2nd volume that can be setup, to allow you some more space, while still being in ddr mode, only because DDR can be very beneficial, especially if you have so much data or so many drives, and if your drives are fairly old, it could come in handy.
[/quote]I have some experience with this. I went from 2-drive redundancy to one as an experiment once. The total time it took was less than 5 seconds. Apparently, only a flag is changed and there is no reorganization, rebuild, copying, or indexing needed. In spite of what the Drobo techs said, there was absolutely no disk activity (as determined by lights & sound) afterwards, and I checked repeatedly for days.
However, when I tried to reverse the process and return to 2-disk redundancy, that option was not available in the Dashboard. Keep in mind that the amount of actual data on the drive had not changed by even a byte.
I gradually removed data from the unit, and eventually the 2-drive option came back, so the amount of space required for this to be enabled is different than the maintenance amount. That is, you may have too much data to enable the option, but once the option is enabled, adding more data has no adverse effects.
Re-enabling the 2-drive option (from 1) took 2 weeks while disabling it took 5 seconds. I advise you plan accordingly if you want to experiment.