Do third-party disk tools work with Fusion Drives, or are you stuck with just Disk Utility?
Disk Utility
If you are running Yosemite or El Capitan, OS X may have changed the way that your boot disk is managed – and how you can maintain and repair it.
How I recovered my broken RAID backups, and got everything working again.
The icon for my 2 TB external drive is greyed out in Disk Utility, and I can do nothing with it. How can I restore its normal function?
When I try to move files onto my hard drive, I have to authenticate. How can I fix this?
When an app ran fine, but crashes in El Capitan, it may be SIP’s fault. Here is how to check, and more about SIP.
When verifying my hard disk, Disk Utility reports that the ‘keys are out of order’. What do I do next?
How to repartition and install El Capitan afresh on an old iMac.
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 Eclectic Light Company 