Q: Start Up disk is full

Although there are things you can do, plan on creating an archive of what you want to keep

in an externally enclosed drive or on some larger capacity storage media; then if you need

to, you could erase or trash the original copies once you have made duplicates.

There are locked items that won't let you empty trash to be rid of, that is because they may

be important to your applications or to the OS X itself; some of these, once gone, will not

let your computer start up again. Be wary of deleting files from the system; only copy your

own works to an external archive before deleting originals; not system files or system apps.

OS X Mavericks (and other)  Remove files and folders from your Mac

• OS X Tips: Where did my Disk Space go?

http://www.pondini.org/OSX/DiskSpace.html

To see what is using the space & where it it, you could use a utility such as OmiDiskSweeper.

This says it will work with as old an OS X as Mt Lion 10.8.+ I see there is a download link here:

https://www.omnigroup.com/more/

There used to be a free version of What Size (on an older OS X I've a version from then) but

now it would cost you. Be very wary of 'cleaning' by use of any application to help performance

since the use of these can kill your OS X and make it hard or impossible to recover lost data.

Do not use a cleaning application or utility to make your OS X work better. You could see what

size and where the files are and then choose to back up items that are only what you installed.

Items that required you to run an installer to put in the system, usually require their uninstaller

to remove all the hidden parts. An item you dragged into the Applications folder may partially

be removed by dragging it to the Trash. Later, when you are sure you want it gone, empty trash.

Backup your computer system and your files to an off-computer archive, not just Time Machine,

before you change the content and character of the creature you've built. It may not like you after.

• OS X: About OS X Recovery - Apple Support

I'd try starting in OS X Recovery and have OS X Utilities/Disk Utility, repair disk and repair

disk permissions; or on a lark try starting in Safe mode to see if that helps. It will check & fix

several items in a similar way that Disk Utility repairs the disk. Then restart normally to test.

• Try safe mode if your Mac doesn't finish starting up - Apple Support

• Using Disk Utility to verify or repair disks - Apple Support

If you are within proximity of an Apple Store with Genius (retail official store) you could call ahead

or use the online reservation method, to set an appointment for their staff to help you resolve this.

• Make an appointment at an Apple Retail Store Genius Bar
• Find an Apple Authorized Service Provider

Always backup, in more than one archive that is not on the original OS X boot volume in your Mac.

{That said, my backup dual HDD externally enclosed drive unit is sitting in a box in a closet.}

Perhaps someone will see your thread & offer other ideas. When I started this, nobody else had.

Good luck & happy computing!

There is no other internal drive to which you can move files. You would have to move them to an external drive, or just delete them.

For information about the Other category in the Storage display, please see this support article. If the display seems to be inaccurate, try rebuilding the Spotlight index.

Empty the Trash if you haven't already done so. If you use iPhoto, empty its internal Trash first:

          iPhoto ▹ Empty Trash

In Photos:

          File ▹ Show Recently Deleted ▹ Delete All

Do the same in other applications, such as Aperture, that have an internal Trash feature. Then restart the computer. That will temporarily free up some space.

According to Apple documentation, you need at least 9 GB of available space on the startup volume (as shown in the Finder Info window) for normal operation—not the mythical 10%, 15%, or any other percentage. You also need enough space left over to allow for growth of the data. There is little or no performance advantage to having more available space than the minimum Apple recommends. Available storage space that you'll never use is wasted space.

When Time Machine backs up a portable Mac, some of the free space will be used to make local snapshots, which are backup copies of recently deleted files. The space occupied by local snapshots is reported as available by the Finder, and should be considered as such. In the Storage display of System Information, local snapshots are shown as Backups. The snapshots are automatically deleted when they expire or when free space falls below a certain level. You ordinarily don't need to, and should not, delete local snapshots yourself. If you followed bad advice to disable local snapshots by running a shell command, you may have ended up with a lot of data in the Other category. Ask for instructions in that case.

See this support article for some simple ways to free up storage space. A common waste of space is old iTunes backups of mobile devices. As illustrated in this support article, select the Devices tab in the iTunes preferences window, select the backups you want to delete, and click Delete Backups. Keep at least one backup of each device that you still use.

You can more effectively use a tool such as OmniDiskSweeper (ODS) or GrandPerspective (GP) to explore the volume and find out what's taking up the space. You can also delete files with it, but don't do that unless you're sure that you know what you're deleting and that all data is safely backed up. That means you have multiple backups, not just one. Note that ODS only works with OS X 10.8 or later. If you're running an older OS version, use GP.

Deleting files inside a photo or iTunes library will corrupt the library. Changes to such a library must be made from within the application that created it. The same goes for Mail files.

Proceed further only if the problem isn't solved by the above steps.

ODS or GP can't see the whole filesystem when you run it just by double-clicking; it only sees files that you have permission to read. To see everything, you have to run it as root.

Back up all data now.

Install the app in the Applications folder as usual. Quit it if it's running.

Triple-click anywhere in the corresponding line of text below on this page to select it, then copy the selected text to the Clipboard by pressing the key combination command-C.

For ODS:

security execute-with-privileges /A*/OmniDiskSweeper.app/*/M*/* 2>&-

For GP:

security execute-with-privileges /A*/GrandPerspective.app/*/M*/* 2>&-

Launch the built-in Terminal application in any one of the following ways:

☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)

☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.

☞ Open LaunchPad and start typing the name.

Paste into the Terminal window by pressing command-V. You'll be prompted for your login password.

The application window will open behind other open windows. When you scan a volume, the window will eventually show all files in all folders, sorted by size. It may take a few minutes for the app to finish scanning.

I don't recommend that you make a habit of doing this. Don't delete anything as root. If something needs to be deleted, make sure you know what it is and how it got there, and then delete it by other, safer, means. When in doubt, leave it alone or ask for guidance.

When you're done with the app, quit it and also quit Terminal.