'Your startup disk is almost full' Mac Error
With the increase in quality of the media we consume, and the always-expanding set of features offered by apps, it is natural that the space they require on the disk drive to function properly has also seen a drastic increase. It is not that surprising them that upon starting their Mac, some users might find themselves looking at a warning prompt with the following message: 'Your startup disk is almost full.' The latest macOS update named Big Sur changed the error prompt a bit with it now displaying a reworded message - 'Warning! Your Mac is running low on disk space,' while also showing the remaining free space on the drive.
The warning message indicates that the startup disk of the system has almost run out of free space. The generally accepted advice is to keep at least 5GB of free space to ensure that your system functions properly. The effects of having no free space on the startup disk may include general system instability and slow performance. Certain apps might also be affected and could start freezing or outright crashing. To fix the situation, users will have to free up some space by either deleting unnecessary files and apps from it or moving data stored there to an external drive or to a cloud storage service.
The first step may sound rather obvious but we often forget to empty the Trash after uninstalling apps or deleting individual files. Over time the space taken up by files still left in the Trash could begin to take up serious chunks of the hard drive. Simply, right-click the Trash icon from the dock panel and select 'Empty Bin.'
The next step should be to organize your Downloads folder. Due to the sheer volume of files we receive from numerous different sources, not to mention the files we download ourselves, the Downloads folder may become clogged up with forgotten images, videos, movies, applications that are no longer needed. The destination is located in /Macintosh HD/Users/Current User/Downloads. Take advantage of the filter options such as size, type, or date to save time in finding the appropriate files to delete instead of having to scroll through everything inside the Downloads folder.
Another way to free up significant space on your drive is to delete any old iPhone backups that might be present there. Frequently syncing your iPhone with iTunes may result in it the creation of multiple backup copies of your phone data. Usually, the backup will take up a significant portion of space as it contains numerous large files such as movies, images, high-quality audio, etc. The recommended method of removing old backups is to launch iTunes, open the Menu Bar, selecting iTunes, and choosing Preferences. A list of all backups created by iTunes should be available there. Users can also delete old backups directly by going to the following location:
~/Library/Application Support/MobileSync/Backup
Make sure that the backups you delete do not contain any important files.