There's a bunch of ways of measuring "usage" for disks, apart from the "how much space is used". There's "how many iops" (vs the total available for the disk), there's how much wear % is used/left for the disk (specific to flash), how much read/write bandwidth is being used (vs the maximum for the disk), and so on.
There's a bunch of ways of measuring "usage" for disks, apart from the "how much space is used". There's "how many iops" (vs the total available for the disk), there's how much wear % is used/left for the disk (specific to flash), how much read/write bandwidth is being used (vs the maximum for the disk), and so on.