How to repartition and install El Capitan afresh on an old iMac.
Disk Utility
My iMac persists in starting up and freezing every morning. How can I stop it?
Why do I see several disk images in the sidebar of Disk Utility?
The new 4 TB hard disk I have just installed in my Mac Pro has become uncooperative. Has it died already?
When my external drive woke from sleep. it needed repair, but Disk Utility cannot help. What should I do?
Which apps SUID and can be ignored in Disk Utility logs?
After breaking the RAID mirror set, my Mac mini Server will not start up. Have I corrupted it?
Does a ‘bitmap error’ mean that my hard disk is about to fail?
Disk Utility warns of SUID files and ACLs. How can I complete repairing permissions?
How secure is an encrypted disk image that I might create using Disk Utility on my Mac?
The Eclectic Light Company 