Unmounted volumes on hard disc
Just had a clean install of Catalina on my hard disc. In disk utility there are 2 unmounted volumes taking up over 600 gigs of space. I’m afraid to restore from time machine backup via migration assistant, because last time I tried this, it wouldn’t finish because of not enough disk space. I called Apple support and they said that I could delete/erase one of these volumes. Unfortunately the person I talked to didn’t seem to know too much about it. What is on the volumes or how can I check to see what is in them? Is it safe to delete them. I have a years worth of back ups from time machine on an external HD also in which I would like to restore from a back up a month ago.
iMac 21.5", macOS 10.15