Seagate USB drive not mounting when on hub

Question

Seagate USB drive not mounting when on hub

I have a late 2008 Macbook on OS X 10.10.2 and attached to that a 4 port Iogear USB 2.0 hub. Into this I had a 2TB Segate USB drive that was working really well as my Time Machine backup drive. After a restart it was complaining about some disk error so I ended up plugging the drive directly into the Mac and running Disk Utility on it and the issue was resolved.

Now if I plug it back into the hub OS X doesn't mount the drive, and going to Apple > About My Mac > System Report... the USB device is not seen. I have tried all the ports on the hub and they work for other devices (USB thumb drive, no-name USB drive, ANT+ adapter, etc) but not this particular drive. When plugged in the drive will spin up and do some work then spin down again.

I have tried a different (new, powered) StarTech USB 2.0 hub and see the same behavior.

However if I use an old USB monitor/keyboard switcher and plug that into the hub (either one) and plug the Seagate into the switcher then it is recognized by OS X. Disk Utility does not see the drive when the System Report does not show it.

So my guess is that the Mac has developed an aversion to this drive on a hub because of it's earlier disk errors. But I don't even know where to look for some config or setting to resolve this.

FWIW, The display of USB devices in the System Report does not make 100% sense as it shows some things on the hub in the level below the hub and other things on the hub that appear at the same level as the hub.

Any thoughts, wisdom, sage advise ?

MacBook (13-inch Aluminum Late 2008), OS X Yosemite (10.10.2)

Posted on Mar 16, 2015 4:52 PM

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Answer 1

my ginger

Level 5

4,904 points

Mar 16, 2015 5:34 PM in response to HoraceWorbleHat

Sometimes the usb ports on the macbook don't put out enough power. Usually a pram reset fixes that. Command/Option/P/R keys for three chimes at startup. Also , have you tried a different usb cable with you external drive to rule that out. I have had it happen where the usb cable will power the external drive, but not allow the computer to read it.

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Answer 2

Mar 16, 2015 6:30 PM in response to my ginger

Well, doing the Command+Option+P+R did make a difference. Unfortunately, now the drive is not recognized when plugged into the keyboard/display switcher either. The Seagate USB drive is powered by a separate wall-wart so power via USB is not an issue. I have tried different USB cables where possible but with no change to the behavior.

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Answer 3

Mar 17, 2015 5:22 AM in response to HoraceWorbleHat

Digging around for any solution I found a Seagate utility for Windows that can modify values on the drive. I installed this on a Windows machine then used it to change then reset all the values for the drive. Now it seems to be working fine again. I am not sure what the Mac does to the drive to change this or how to reset the values if all you have is a Mac. Maybe it is a sign that I should go back to Windows...

In any case the problem appears to be resolved now as the drive has reconnected fine again this morning.

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Answer 4

my ginger

Level 5

4,904 points

Mar 17, 2015 7:26 AM in response to HoraceWorbleHat

So, was it that your external drive was a NTFS formatted drive? If so, that would explain the problem of disk repair in mac as the mac os only uses fat 32. for other that mac os extended . While it will read NTFS disk,it cant repair them. Was that the case?

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Answer 5

Mar 17, 2015 7:56 AM in response to my ginger

I didn't know that Time Machine backups could run on an NTFS formatted drive. It would be superlative if Time Machine supported NTFS, CIFS or NFS then I could shove the backups to a network share rather than having to use an Apple formatted drive.

In my case the drive is formatted for "Mac OS Extended (Case-sensitive, Journaled)" (HFS+ ?). The Disk Repair utility did eventually seem to fix the disk errors that were being reported. I don't know if the disk errors or the use of Disk Repair were what lead to the USB recognition issue. The Seagate utility lets you set things such as whether or not the activity light comes on, the idle sleep time-out, etc. Setting all those values to something different then back again seemed to have resolved the USB problem. It was unrelated to the format of the data on the drive.

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Answer 6

my ginger

Level 5

4,904 points

Mar 17, 2015 8:13 AM in response to HoraceWorbleHat

Usually an external drive that is setup with mac os extended journaled with a GUID partition doesn't have those problems. I think your right that the disk repair did something to the recognition of the drive. Is this a SSD drive?

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Answer 7

Mar 17, 2015 9:45 AM in response to my ginger

To be honest I don't know what the Disk Utility may have done, it took a couple of runs before it ran without reporting any issues.

I did also run a trial download of Stellar Phoenix Mac Data Recovery on the drive first but it crashes after reading the drive structure. Their unlicensed trial version can't fix anything I was just thinking it may say what was wrong at the time. BTW, contacting Stellar support I found out that drives used for Time Machine are "not supported" - and it lets you know this by crashing, totally non-impressive.

The drive is normal 2TB spinning media (Seagate STAY2000102) not SSD. Running the Seagate tool on the drive seems to have corrected the issue so I view this problem as resolved and it was certainly a better option than re-formatting the drive - which seems to be the most common answer for this type of issue from what I have found.

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Answer 8

my ginger

Level 5

4,904 points

Mar 17, 2015 10:43 AM in response to HoraceWorbleHat

Well I'm glad you solved your problem.

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