How to check if journaling is enabled or not on my disk? As usual the main internal drive on which macOS gets installed is journaled. I was going through some Ask Different posts in which there was something mentioned as Disk journaling which saves you from file corruptions but each time it registers the status of your file at the present time.These registrations might be having a huge impact on your CPU and Disk (My Assusmption), so is there any way by which I can check if my disk has journaling turned on or not and if it has how to turn it off via terminal?

When I click on File Menu option via the menu bar after selecting my main Disk, this is what I get - Journaling is greyed out (I guess this option lights up if and only you are in recovery mode)
You do not specify which version of macOS you are using. I will assume the current version (macOS 10.13.3).

Open the Disk Utility application and select the volume you wish to check. In the image below, "MyFish" has been selected.


  Note: For a better view of an image, either click on the image or open the image in a new window.


Next, click on "File" in the menu bar. In the pulldown, you will see "Enable Journaling". If "Enable Journaling" is grayed out, then journaling is enabled, otherwise journaling is disabled. Below, the image shows the volume to have journaling enabled.



The older versions of macOS, would allow for journaling to be disabled directly from the Disk Utility application. With macOS 10.13.3, journaling can be disable by using the diskutil command. Below is the command to disable journaling for the "MyFish" volume.

diskutil  disableJournal  MyFish


Similarly, journaling can be enabled by using the command below. As stated earlier, this can also be accomplished from the Disk Utility application.

diskutil  enableJournal  MyFish