Disks & storage
Check how much disk space is left — With Disk Usage Analyzer or System Monitor.Check your hard disk for problems — You can test your hard disk for problems to make sure that it's healthy.Manage volumes and partitions — Understand what volumes and partitions are and use the disk utility
to manage them.Test the performance of your hard disk — You can run benchmarks on your hard disk to check how fast it is.Wipe everything off a removable disk — Remove all of the files and folders from an external hard disk or USB flash drive by formatting it.