Booted Into Safe Mode, but external USB HDD doesn't show up?

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Etrecheck – System Information

NewbMacUser wrote:

Does anyone know why?

See here: See here: OS X: What is Safe Boot, Safe Mode? - Apple Support

Some features aren't available in Safe Mode

Some OS X features aren't available when your Mac is started in Safe Mode. For example, you can't use DVD Player, capture video in iMovie, or use audio input or output devices. Some USB, FireWire and Thunderbolt devices may not be available. Wi-Fi networking might be limited or unavailable depending on the computer and OS X version you're using.

I don't know which ones are compatible and which are not, and it may be Mac-specific.

NewbMacUser wrote:

Thanks for your replies!

I'll try mounting the HDD in Disk Utility.

Barney,

I just checked this link and it says "Safe Mode in OS X v10.6 or later also disables File Sharing. This means you can't mount Time Capsule disks or volumes served by computers started in Safe Mode." OS X: What is Safe Boot, Safe Mode? - Apple Support

That actually means you can't share files from a Mac booted into Safe Mode, not necessarily that you cannot connect to another Mac from a Mac booted into Safe Mode. File Sharing is a service of the host machine, not the client. If the Host is in Safe Mode, it won't work. If the Client is in Safe Mode, it may work.

NewbMacUser wrote:

Could someone please help me out?

I'm not sure how as either your drive or your USB ports are not working in Safe Mode. That is one of the possible issues with Safe Mode. You could try other types of drives, making sure you connect them directly to the Mac and not a hub.

How about a Firewire drive?

NewbMacUser wrote:

Does anyone know of a way for me to copy my files off the Mac's HDD? I'm really desperate here because in Disk Utility it says that the Mac's HDD is failing.

You need a drive that will work on your Mac in Safe Mode. I'm not sure anyone knows what that may be, though. Apple is rather vague on that.

If the drive is failing, buy a replacement, install it, reinstall OS X using Internet Recovery, then get an external enclosure for the old drive. You may be able to mount it and get your files off of it.

NewbMacUser wrote:

Disk Utility is now telling me that the Mac's internal HDD is definitely failing. I'm trying to copy my important files off now, but it's a slow process because the spinning beachballs keep appearing which interrupt the file copy process.

Edit: I'm getting spinning beachballs in Safe Mode.

2ndEdit: I'm trying to run Time Machine, but it's realllly slow and the spinning beachballs are interrupting it.

That why I suggested pulling the drive. The drive is just eating itself alive. You may have better luck recovering the data if the drive isn't running the OS, too.

NewbMacUser wrote:

Thanks!

To be able to copy the files off, is the best thing I can do just to buy a new external USB HDD and copy the files from the Mac to the USB HDD?

No. The best thing to do is buy a new internal drive. Use Internet Recovery to reinstall OS X.

Also, purchase an enclosure. While booted from the new hard drive, you can put the old drive into the enclosure and connect the old drive up via USB and copy over what is still accessible. It may be difficult to do and you may need to have it done for you, you are just making the near-dead drive work harder causing more damage. iFixit.com has very good instruction sheets on how to replace hard drives in most Macs.

If it is a 2.5 inch drive (laptop size), then you could use a cable like this: Apricorn SATA Wire Notebook Hard Drive Upgrade Kit with USB 3.0 Connection ASW-USB3-25 (Grey)

You don't need the software, just the cable that comes with the kit.

Does the drive show in Disk Utility?

See mount section in 1st linked article.

Disk Unmount Using Terminal

Disk Utility – Force Mount Disk