mac does not see external hard drive

Just thought of something... Since this driver is third party (not Apple), if you do a Safe Boot, it will not be loaded.

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

It's basically starting up with the Shift key held down. In Safe Mode, only Apple's drivers are used. See if that makes your external drive read-only again. If that works, and your Mac has enough free space on its internal drive, you can copy off some or all of your valuable data. Otherwise, shut down and disconnect that drive. Get another external drive. Before starting to use it, format it for Mac (using Disk Utility), if it's not already. Start up again in Safe Mode and copy off the rest of the data to the new drive. Then, you can reformat that Samsung external drive for Mac, and keep using it.

Thank you - although no luck in safe mode either. No sign of the HD.

I restarted again normally, and the HD appears as "remote disc" with a CD icon, but I can't click on it, and it can't bring up any information about the device.

One last attempt: do you know where drivers are installed on a Mac, if one chooses the default location when installing? Thought maybe I could delete the installed driver directly from the hard disk (I'm clearly a novice, so bear with me), but I can't seem to find where it has been installed.

In Safe Mode, third-party drivers are not being used, so it would be the same as not having it installed. Sometimes, the drive is there but its volume is not mounted by the system. If you did not look in Disk Utility when starting up in Safe Mode, you should try doing it again. Open Disk Utility in Safe Mode. If you see the Samsung drive in the sidebar, with a volume indented below the drive, select the volume and click Mount.

Also, you may want to try downloading the driver software that I linked to in a previous reply

http://www.seagate.com/support/downloads/item/samsung-ntfs-driver-master-dl/

It may be the same software (or newer version of same software) that was on the Samsung drive. If it is, you may be able to use it to uninstall the driver. OR, if you can't do that, install it again. If this version is newer than the one you installed, it may help make the drive accessible again.

SUCCESS!!!

I was able to remove the driver using the link you posted, which made the HD appear in Finder upon restart. I then reinstalled the driver from the Samsung folder, which didn't seem to work. I uninstalled again, and reinstalled the driver from your link. Now it works!! (you can't tell, but I'm doing a happy dance).

Thank you so much for taking the time! I am admittedly lost when once in a blue moon something Mac related doesn't work 🙂

(And just fyi - the "mount" option didn't appear in disk utility in safe mode either, nothing changed).

Good news! 😎 It wasn't "doomed" after all...

You should get another drive to keep your valuable data backed up, because hard drives are known to fail without warning. And after it's backed up, you can consider reformatting that Samsung drive for Mac (using Erase in Disk Utility), so that you don't need to rely on a third-party driver to access it.

The suggestions here sound great but they're not the answer for me.

My wife and each have an iMac (models 7,1 and 8,1). One has a single external drive, the other has two. All three externals (from OWC) have run without problem for a long time without issues, yet all three are now invisible, seemingly within the last 24 hours.

We have installed no OS updates lately (we're still on 10.8.5). But yesterday one of my HDDs — the first of two in a daisy chain — developed a dreaded clicking sound, every six seconds or so, i.e. possible symptoms of death. It was after that that I noticed that neither HDD in the chain was available any more. And then I found that my wife's external HD was also invisible. The drives fail to show in Disk Utilities, in System Report or when running "diskutil list" in Terminal.

We had the HDDs connected through FireWire 800 ports. We have since tried, where possible, using FW 400 and USB 2.0 ports. We have shut down, disconnected all device cables except for the keyboard. After restarting, connecting by USB still fails to help. USB sticks do mount.

Other than the clicking sound, all I can think is that one of the iMacs have been hit by the ransomware KeRanger, as I recently updated the susceptible Transmission app (and have since installed the fix). That doesn't seem likely though. KeRanger reportedly encrypts files and issues a ransom demand. Certainly our internal files — presumably the first to be attacked — seem fine, and there has been no ransom demand. Also, our iMacs fail to see each other on our LAN (making it largely useless), so a successful malware attack across the network seems improbable.

Help please!

One drive can fail at any time, but it is unlikely for two to fail at the same time. Three failing at the same time is HIGHLY unlikely. Unless they have something in common.

Two of them had a common connection point. An odd sound coming from the drive sounds like a hard drive failure. Remove that one and connect the second drive directly to the Mac. Sounds like you probably did that, when you tried using the USB port instead of FireWire. With FireWire, a problem with one drive can affect the other drive. However, I don't know how it could affect the third drive connected to a different computer.

Do the drives seem to be running (you can hear them spinning and see blinking lights)? When you run System Profiler, do the drives still appear as connected hardware?

Thanks for your reply, Kenichi.

Two of the HDDs run at a constant speed, their lights on but not blinking. The most interesting sounds come from the HDD that I heard clicking yesterday. At the moment it is connected by USB (2.0). On listening more closely what is happening is that it spins up, clicks, then spins down. I would guess it's trying to interface with the computer. The click may be a control switch that turns off the spinning. I don't know if that's the click of death or simply a control doing what it's meant to if it doesn't like something. On FireWire 800 and 400 there is barely any flicker, the drive spins more quietly, if at all, and I hear a quiet buzz followed by two even fainter double clicks, sort of like the down-and-up clicks of a mouse but quieter.

Regardless which HD I wire up, in About this Mac > System Report the only drive that appears is the internal one. This is regardless of whether connected by daisy chain, direct FW or direct USB. And on both iMacs.

How are these external drives connected to power? If you have an "octopus" under your desk(s), the external drive enclosures may not be getting enough power. Are they connected to the same power strip (surge suppressor) as your iMac, printer, second display, desk lamp, numerous power adapters, etc? There's a limit to the current that can flow through one wall outlet. That could cause the odd behavior of the one making funny sounds, and the other one not responding at all.

duncantho wrote:

Other than the clicking sound, all I can think is that one of the iMacs have been hit by the ransomware KeRanger

If you were infected with KeRanger and it had "detonated" after its 3-day waiting period, it would encrypt files, also renaming those files with an ".encrypted" extension. There would also be a file named README_FOR_DECRYPT.txt in any folder containing such encrypted files. If you're not seeing that, the problem is not due to KeRanger.

Sounds like a physical failure to me.

Good morning Kenichi

I've reduced the power strip to just the computer and one external harddrive (through a power adapter), with no other adapters or devices attached. Still no luck. For what it's worth I do think the HDD with the clicking sound has failed. That doesn't explain why the backup HD, which is a two-partition clone of the internal and the failed external drives, remains invisible.

Regards.

Hi thomas_r.

I have found none of the files you mention. Also, there's a suggestion online that users (such as I) who updated Transmission through the app itself — rather than going to the website — avoided the problem. Not sure how reliable that is but it points away from the malware theory.

Cheers.

duncantho wrote:

Also, there's a suggestion online that users (such as I) who updated Transmission through the app itself — rather than going to the website — avoided the problem. Not sure how reliable that is but it points away from the malware theory.

Yes, that appears to be correct. For all the bashing that Sparkle updates have gotten over the last month, in this case, Sparkle was the secure option. Sparkle is smart enough that it won't do the update if the code signatures on the app being updated and the new version don't match, and in this case, they didn't.

My HDD manufacturer (OWC/macsales) got back to me yesterday with a suggestion which I've been unable to test, having already taken my HDDs to a repair shop. Anyway, if the suggestion works it would be a lot easier and cheaper: just reset the NVRAM.

The instructions here for resetting are from macsales differ from Apple's in terms of when and how long you hold down keys on start-up:

Shut off you system

Hold down the CMD+OPTION+P+R keys at boot up

These keys must be down before the computer tones.

Allow the computer to tone at least 3 time before releasing the keys.

If you have a Wireless Keyboard you will have to wait to the count of 3 before holding down the keys so that the system will pair with the keyboard first.

Courtesy of macsales, here's the link for Apple's instructions: How to Reset NVRAM on your Mac - Apple Support

Just for the record,

Regards

OWC makes the enclosure, not the actual hard drive mechanism inside.

Reset PRAM (or NVRAM) is a commonly done procedure, but I don't think anything in PRAM is applicable to accessing connected storage devices. And it does not explain why the problem occurred on two different Macs at the same time. Certainly does not hurt to try it.

The best test is what the repair shop is doing. They will no doubt test the hard drive mechanism by itself, apart from the enclosure, to see if it is still working. Hopefully, the problem is the enclosure, not the hard drive. You can put the hard drive in a new enclosure.