I have a customer with 75% disk used average across all nodes. Due to organization, they may not be able to refresh hardware until next calendar year and want to know when they will start hitting issues with free space. This is not asking best practice or even allowable practice but what is the lowest free space Vertica can tolerate? I suggested leaving 10-20% free but asked them to run a metric to see the highest intraday disk usage over past 30 days to get an idea how storage was being used.
Also, they asked whether it is safe to replace disks with bigger ones. I suppose if they were able to add nodes, they wouldn't be having this issue at all. Any recommendations on increasing storage by replacing disks? Would they have to go one at a time and rebuild RAID then rebalance from buddy? They don't have a regular backup going.
