Saving data going from Raid 1 to Span

[JapanMCJ]

Hello,
I have a BA NAS 220 with two 2TB drives in Raid 1. I have about 500G of videos that I want to keep and about 1TB of Time Machine backups that I want to get rid of. My plan was to change the RAID config from RAID 1 to Span. Then delete one of the 2 drives in the NAS 220, reformat it (to clean off the TM data) and then put the 500G of videos back on it from the 2nd drive in the NAS 220. Will that work? Is there a better way to do this?
I would really like someone to verify that setting the config to SPan will not automatically wipe the drives.

Once that is done, I would wipe the second drive, set the config to Raid 1 and let it "sync" back up so that both drives are identical with only the 500g of videos.

Note: I would just wipe the 1TB of TM data but I can't see it in Mac finder or Windows explorer.

 

[WyomingKnott]

Changing RAID levels usually wipes all existing data (some RAID software will do it nicely). The simplest thing is to copy them to an external drive, _verify_ the copy, and then change your RAID. Copy the saved data back.

Two suggestions. First of all, the Time Machine software will probably let you browse your backups and delete older data, perhaps even set a policy about the max number of copies / max amount of data usage allowed.

Second, while I know nothing about that NAS, or any NAS, RAID1 can often be "broken," removing one drive from the RAID set and leaving the other as a standalone drive. If the management software will let you do this, you just reformat the removed drive and use it as a second drive, or even span the first onto it. I would recommend using it as a second drive rather than spanning. One for your data, one for Time Machine, and the one can't eat space that you meant for the other.

Hoping that this helps

 

[JapanMCJ]

Best answer selected by JapanMCJ.

 

[JapanMCJ]

Thanks, the fact that it will most likely wipe the data, answers the question. I think you are right that the best method is to use an external drive.
FYI...TM is extremely limited in options you can set. It is really meant for the average user that just wants to hit one button and forget about it forever. With that said, you can TYPICALLY find the data to delete but for some reason, on this drive I can not, which leads me to a complicated solution for a simple task. Thanks again for your help.