What happens if I don’t see disk to install macOS?

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What happens if I don't see disk to install macOS

If you are trying to install macOS and do not see the disk you want to install it on, there are a few potential causes and solutions to try.

Causes

Here are some common reasons why you may not see the disk you want to install macOS on:

  • The disk is not formatted properly for macOS installation
  • The disk is not connected properly or detected by your Mac
  • The disk does not have enough free space for the macOS installation
  • The disk is having hardware or connection issues
  • The macOS installer is not detecting or showing the disk correctly

The disk is not formatted properly

For the macOS installer to recognize a disk and allow installation, the disk needs to be formatted properly. Typically, the disk needs to use a macOS compatible format like Mac OS Extended (HFS+) or Apple File System (APFS).

If the disk is formatted with a Windows format like NTFS, ExFAT, or FAT32, it will not be visible to the macOS installer. Reformatting the disk to a macOS compatible format before trying to install should resolve this.

The disk is not connected or detected

Obviously the macOS installer cannot see a disk if it is not actually connected to the Mac or if the Mac cannot detect it for some reason. Some things to check:

  • Make sure the disk is fully plugged into the Mac using the appropriate cable connections.
  • Try connecting the disk to a different USB, Thunderbolt, or other port on the Mac.
  • If using an external enclosure, try taking the disk out and connecting it directly inside the Mac if possible.
  • Check Apple’s Disk Utility to see if the disk shows up there but not in the installer.
  • Restart the Mac and try again, sometimes disks can take a moment to be recognized.

Not enough free space

The macOS installer requires a minimum amount of available free space on the target disk in order to install. This is generally around 10-15GB at a minimum.

If the disk is nearly full or does not meet the minimum space requirements, the installer may not show or recognize the disk. Frees up space by deleting unused files and applications and then try installing again.

Hardware or connection problems

Faulty or failing hardware in either the disk itself or the connection cables/ports can also prevent proper detection by the macOS installer. Some things to try:

  • Try a different cable if using an external disk.
  • Try connecting the disk to a different Mac.
  • If an internal disk, try reseating the SATA/power cables or try a different SATA port.
  • Listen for any odd noises from the disk indicating hardware failure.
  • Use Disk Utility to check for and repair any disk errors.

macOS installer detection issues

In some cases, there may be bugs or compatibility issues with the macOS installer that prevent it from properly detecting eligible disks. Things to try:

  • Use the latest macOS installer version available.
  • Try restarting the installer or Mac if the disk is not showing up.
  • Try installing from USB or Internet Recovery instead of a local installer disk.
  • Use Disk Utility during installation to erase/reformat the target disk first.

Solutions

If you have determined the likely cause preventing the macOS installer from detecting your disk, here are the general solutions to resolve the problem:

Reformat the disk

If the disk is formatted incorrectly for macOS, reformat it to a compatible format:

  1. Open Disk Utility on the Mac.
  2. Select the disk.
  3. Click Erase at the top.
  4. Choose Mac OS Extended or APFS format.
  5. Name the disk.
  6. Click Erase to reformat the disk.

Resolve connection or detection issues

For hardware, cabling or connection detection issues:

  • Swap out cables for known good ones.
  • Try different ports or direct internal connections if possible.
  • Check for physical damage or failures on disk or enclosure.
  • Update Mac and SSD/HDD firmware if applicable.

Free up disk space

If the disk is too full, make space by:

  • Emptying Trash and Downloads folders.
  • Deleting unused apps and files.
  • Moving files to external storage.
  • Uninstalling unneeded programs.

Aim for at least 15-20GB of free space for the macOS installer.

Try a different installer source

If using a local macOS installer drive, try downloading the installer again or use a different source like:

  • USB installer drive – Create bootable install USB.
  • Internet Recovery – Hold Command-R on boot to access over internet.
  • Apple Installer on App Store (requires working macOS version)

Use Disk Utility

The macOS installer’s Disk Utility can reformat disks to be recognizable before installing. On the installer screen:

  1. Open Disk Utility.
  2. Erase/reformat disk.
  3. Close Disk Utility when done.
  4. Return to installer to select disk.

This should make the disk visible to install macOS on.

Best Practices

Follow these tips for smooth macOS installation when selecting a disk:

  • Use a disk with at least 15GB free space – The installer requires room to work.
  • Directly connect the disk – Avoid issues with external cables or connections.
  • Format the disk prior to installing – Use Disk Utility to erase/format.
  • Use APFS format – The newest Apple File System format.
  • Perform a test run first – Install to an external drive to test entire process.
  • Use latest installer version – Up to date installer has latest bug fixes.
  • Backup important data – In case anything goes wrong.

Following best practices when selecting the disk for your macOS installation can help avoid potential issues down the line.

Troubleshooting Tips

If you still do not see the disk you want when installing macOS, some additional troubleshooting tips include:

  • Try disconnecting all other disks and drives to isolate the target disk.
  • Boot into macOS Recovery or Apple Hardware Test for diagnostics.
  • Reset NVRAM/SMC on Mac to clear out any glitches.
  • Check cabling for damage, try swapping out if possible.
  • Use disk repair utilities like First Aid to fix errors.
  • Update Mac and drive firmware to latest available.
  • Try installation on a completely different Mac if possible.

Persistent disk detection issues may indicate hardware problems requiring professional service. Apple also provides additional macOS installation troubleshooting steps online.

When to Seek Professional Help

In most cases, users can resolve a disk not showing up during macOS installation themselves using the steps here. But in some instances professional help may be required, such as:

  • Physical damage to disk or Mac hardware.
  • Failed drive requiring data recovery assistance.
  • Advanced disk partition, formatting or firmware complications.
  • Hardware compatibility issues with Mac model.
  • Unresolved software or macOS installation bugs.

Apple Stores and authorized service providers can diagnose more complex underlying hardware or software problems preventing disk detection during installation. They also have access to internal Apple resources and engineering teams if needed.

Professional help avoids spending time and money on parts or repairs that may not fix the root cause. Experts can also safely handle disk data recovery and migrations if required.

Conclusion

Not seeing the disk you want to install macOS on is a common problem with several potential causes. In most cases it comes down to improper disk formatting, lack of free space, loose connections, or software glitches that can be resolved by an average user.

Following best practices like formatting disks correctly before installing, checking physical connections, and isolating variables can help avoid and troubleshoot issues. For more serious or complex problems, seeking professional assistance can quickly get your disk recognized and macOS installed correctly.

Cause Solution
Incorrect disk format Reformat disk with Disk Utility
Not enough free space Delete unused files to free up space
Loose or faulty connections Check cables, try different ports
Hardware failure Replace faulty cables or disk
Software or detection bug Use latest macOS installer, update firmware

With focus and by methodically working through potential fixes, most users should be able to get their disk recognized by the macOS installer. Seeking professional help is wise if problems persist or advanced recovery is needed. Patience and care when installing macOS will avoid headaches down the road.