External Hard Drive will not mount through USB Hub.

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Level 1

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External Hard Drive will not mount through USB Hub.

The Hard Drives are ok. If I plug them directly into my iMac (3 weeks old and update to 10.7.1) they mount fine. But they wont show up if I plug them into my USB Hub that is plugged into my iMac. I have had THREE USB Hubs and all of them have had problems. I have USB flash drive that sometimes shows up and a iPhone that will show up in iTunes when I mount it through the hub.

Is there a program (in the system or share/freeware) that will force the Mac to scan and mount them?

thanks - Otto.

iMac, Mac OS X (10.7), 27" - 16gb Ram | 2TB/205GB HD

Posted on Aug 21, 2011 7:25 PM

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Answer 1

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rkaufmann87

Level 10

140,274 points

Aug 21, 2011 7:32 PM in response to nightotter

If you have narrowed it down to the hub then that is what you should be troubleshooting. If the drives are getting their power from the hub that might be the issue. Also when you're posting please give specifics like makes and models otherwise we're shooting in the dark. If you are using WD drives that could be the problem there too, they tend to have a wide variety of issues with OS X.

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Answer 2

babowa

Level 9

78,097 points

Aug 21, 2011 7:34 PM in response to nightotter

Do the hubs have their own power supply or are they powered by the Mac's USB port? I'd guess that could be a problem because the USB port may not have enough power for the hub and to read/write the drive(s)?

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Answer 3

nightotter Author

Level 1

7 points

Aug 21, 2011 8:04 PM in response to nightotter

Thasnks for the ptompt reply folks. The HUB is a 4-port Belkin, with a power supply. The Hard Drive are each 1 TB. The run on the power from the USB. They are a Seagate and a Toshiba. Now that you both mention the power issue, maybe that is the problem. But it has mounted before. Sometime it's work and sometimes it doesn't. My Flash Drive will show up as will my iPhone or iPad or iPods. But the Hard Drives are having a problem. It seems very sensitive. Sometime when I dismount the Flash Drive, the Hard Drive will dismount too, like it was hanging on a thread and the dismounting of the Flash Drive knocked it off.

I was hoping the Disk Utility might have some scanning feature. I remember WAY BACK in the old OS (9 and before) there was a program that scanned for connected devices. I was hoping there might be something like that which could help.

Thanks again.

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Answer 4

rkaufmann87

Level 10

140,274 points

Aug 21, 2011 8:09 PM in response to nightotter

The issue is the EHD's are not getting enough power. Going forward never buy EHD's unless they have their own power supply. I would recommend either connecting directly to the iMac or replacing them with higher quality devices. The EHD's I like to recommend are:

OWC Mercury Elite Pro series

LaCie d2 Quadra series

G-Tech G-DRIVE series

All are similar in quality and features. Yes they're probably more money that what you paid however they're worth it. I use the LaCie's however I wouldn't hesitate to use the OWC or G-Tech's either.

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Answer 5

babowa

Level 9

78,097 points

Aug 21, 2011 8:26 PM in response to nightotter

My Flash Drive will show up as will my iPhone or iPad or iPods.

Those will show up because they don't require that much power - but 1 TB hard drives are another matter. Aside from the power issue, I'd also seriously consider drives which have Firewire as that is considerably faster than USB. And, I agree with Roger on his recommendations - I have one OWC and two LaCie's - all are Firewire (actually they all have FW 400 + 800, USB, and eSata ports) and all have their own power supply.

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Answer 6

nightotter Author

Level 1

7 points

Aug 21, 2011 8:31 PM in response to nightotter

Thanks ot you all, you were all corrent, great community. I will use the present HD's as offline backups and pick up 3TB linked above. Thanks again! Otto.

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Answer 7

rkaufmann87

Level 10

140,274 points

Aug 21, 2011 8:34 PM in response to nightotter

Your welcome.

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Answer 8

Aug 21, 2011 10:48 PM in response to nightotter

You might also take a close look at your powered hub. Some of those have a small selector switch on them somewhere which allows settiing it to use bus or self power. If yours has such a switch, make sure it is not set to "bus".

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Answer 9

nightotter Author

Level 1

7 points

Aug 22, 2011 7:01 AM in response to Don Archibald

Thanks Don. My HUB doesn't have that switch, but I will look for one in the future. Otto

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Answer 10

Jan 20, 2014 8:21 PM in response to nightotter

I know this is an old post, but I have a similar and somehow different problem.

My new WD My Book Studio 3TB drive works well through a powered USB3 hub when the OS is freshly booted. However, once unmounted and unplugged the USB3 hub, it won't mount by plugging back the hub without rebooting. Does anybody have similar experience?

Thanks!

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