IMac is not detecting external USB hard drive

I restored my iMac (mid 2011 - i5 quadcore - 1TB - 16gb Ram - Lion 10.7.3) and my Macbook Pro (2010 Core 2 - 8gb Ram - Lion 10.7.3) I have a 1TB Toshiba external portable USB 3.0 hard drive.
The drive connects and recognizes quickly and works without any issues on the MBP, on the iMac on the other hand it will not detect in system profile or disk utility. Occasionally when plugged in the drive will spin up and stay powered on, other times on plug in, the indicator light will flash quickly and power off. The drive is fairly new, lightly used, and I repeat has NO issues with the MBP. The iMac will read flash drives and USB devices without issue except for this external hard drive. Also when I restart if the external drive is plugged it it will hang until I remove it. Drive is partitioned 86gb in MS Dos with Master Boot Record profile, and the remaining space is partition 2 formated as Mac journaled.
I am up to date on all updates from apple, and at a complete loss as to what to do next.
Thanks in advance for all your help

What version of firmware are you running on the 802.11ac?
There is a 7.7.1 update with USB fixes - http://support.apple.com/kb/DL1665
After my update to 7.7.1, I still cannot see the Seagate 3TB HDD.
The disk works on a 2nd Gen 802.11n Extreme.
This is

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New Airport Extreme -802.11 ac model is not detecting my USB Hard drive

My new Airport Extreme -802.11ac model is not detecing my External USB HDD when connected via the USB port in the Airport Extreme.
I'm using a Seagate USB HDD 3TB, and it's working when i connect my previous generation Airport Extreme router.
Looks like the new version is not detecting my HDD.
Please help.
Cheers
SK

What version of firmware are you running on the 802.11ac?
There is a 7.7.1 update with USB fixes - http://support.apple.com/kb/DL1665
After my update to 7.7.1, I still cannot see the Seagate 3TB HDD.
The disk works on a 2nd Gen 802.11n Extreme.
This is

2.5" external USB hard drive not recognized by my iMac

I have a small 2.5" external USB hard drive that my intel iMac will not mount or see. My 12" G4 Powerbook sees it fine and it is formatted in Mac OS Extended. My iMac is bootcamped and XP on my iMac sees the drive but not OS X Tiger on the iMac, (wierd) I have Tiger on both my Macs too.
Why does the intel based OS X refuse to see this external 2.5 HD. It sees a 3.5" USB one I have but not the small one. I know it is software.

Hey coby,
Well thanks for the star. Not sure I deserve it.
i then tried connecting the drive to each USB port again, and voila! i have found one it works in. I guess my computer's ports must be a little worn.
Hmm well try looking inside and see if there's some smutz in there, if the contacts are dirty or bent or worn.
i was starting to think i would have to go out and get a USB hub to give it some more power.
Is it powered off the USB? If so that actually might be a good idea since that puts a lot of strain on the connectors. Even if it's self powered it might be a good idea since it would take the strain off an obviously flakey USB.
richard

External USB Hard Drive not showing up on Time Capsule

Hi all,
I have a 500 Gb Time Capsule that used to be able to detect my external USB hard drives. I had to store my things for a while and have just started using the Time Capsule again. The TC works fine, however, the same USB external hard drives I used to connect to the TC are not showing up anymore :s They show up on the desktop when I connect them directly to my MacBook via USB. I have been through most of the file sharing options in Airport Utility and System Preferences but have not been able to solve this. I can't think of any settings that would have changed from when they were showing up in the past. Any help would be greatly appreciated. Thx

yosemite won't work with ntfs drives for some reason, i've had the same issue with my toshiba. i thought ok lemme buy another one, and transfer it over maybe it's a driver issue which i've tried over and over, apple support can't figure it out.
here's a simple fix, but the problem is i have an external where all my photography and video files are stored, so i can't access them right now and it's making my life ****.
http://guides.macrumors.com/Formatting_an_External_Device
that does work and make the drive mountable now, but problem being i can't obviously reformat the old drive and lose everything. once the new drive is formatted for mac i can't plug it into a pc to transfer the files from. which is the only problem now. but formatting the drive for mac only DOES work. but you're just screwed and not able to use it ntfs. hope the link helps SOME people.

External USB hard drives working very slow and/or not recognized. Help!

This probably started after my Yosemite upgrade, but my external usb hard drives either aren't working well or not being recognized. It's taking forever to write files to my external Seagate Free Agent USB 2.0 through front ports and my thumb drives aren't mounting (they have shown up for a second or two, then nothing). Is there a fix? I'm on an early 2008 mac pro with Yosemite 10.10.2.
Thanks!

Do an SMC reset using this slightly-modified procedure:
Resetting the SMC for Mac Pro, Intel-based iMac, Intel-based Mac mini, or Intel-based Xserve
1.Shut down the computer.
2. Unplug the computer's power cord.
[2a. Press the power-on button to discharge the power capacitors.]
3. Wait fifteen seconds.
4. Attach the computer's power cord.
5. Wait five seconds, then press the power button to turn on the computer.
in all cases, the stated times are recommended minimums, and there are no maximums.
Intel-based Macs: Resetting the System Management Controller (SMC) - Apple Support

External USB hard drive not being recognized

Hello! I'm sure this has been posted before, but excuse my naivety with this sort of thing...
I have a mac mini 10.5.6 (1.83 GHz Intel Core 2 Duo) and I run the Time Machine function to an external usb hard drive. The hard drive worked fine (plugged into the usb port on an older keyboard), but I went out and bought a new aluminum apple keyboard (because they look so cool ^_^ ) - I plugged the external usb drive into the keyboard and it wasn't recognized, so I tried plugging the external drive directly into the mac mini, but it is still not recognized. It is not showing up in Disk Utility or in System Profiler
Help? I'd hate to have to give up this fancy keyboard...
Thank you!
Dr. E

I believe I had my external drive plugged into the (old) keyboard because with the old mac that I had didn't have a free usb port for it - so when I got the mini I just plugged things back in where they were. But I have always had the Time Machine back up to this drive (connected to the keyboard) though it has been slow (another reason I thought the new keyboard was a good idea).
I tried restarting the computer without the alu keyboard plugged in, but same problem of no drive showing up.
Here is what System Profiler has to say about my drive:
USB2.0 Storage Device:
Capacity: 93.16 GB
Removable Media: Yes
Detachable Drive: Yes
BSD Name: disk1
Product ID: 0x6830
Vendor ID: 0x04b4 (Cypress Semiconductor)
Version: 0.01
Serial Number: DEF107920F07
Speed: Up to 12 Mb/sec
Manufacturer: Cypress Semiconductor
Location ID: 0x3d130000
Current Available (mA): 100
Current Required (mA): 0
Mac OS 9 Drivers: No
Partition Map Type: GPT (GUID Partition Table)
S.M.A.R.T. status: Not Supported
Volumes:
USB:
Capacity: 92.84 GB
Available: 53.14 GB
Writable: Yes
File System: Journaled HFS+
BSD Name: disk1s2
Mount Point: /Volumes/USB
I don't know the brand or model as it has 'always' been in the case that in which it currently resides and I didn't physically buy the thing :\ I do know that no software was installed with the drive as I assumed that when I put all the old info from the original mac to the mini that it was the sort of thing that would carry over.
Sorry I'm not terribly helpful - Thank you!
Dr. E

C30: Booting from external USB hard drive

I carry my OS on an external portable USB drive, and then make use of whatever hardware is available where I visit.
I recently attempted to boot a Lenovo C30 Thinkstation with this external drive, and was unable to do so. In looking at the BIOS settings, there is no option to boot from USB (other than floppy(?!?) or memory stick).
Is it possible to boot from an external USB hard drive, and if not, why?
jerry

The boot sequence section of our setup menus has been troublesome to say the least (at least through the development phase). There are various reasons why it is the way it is now....from spec requirements to customer requirements. So long story short it really needs to be this way, even though situations like the one you encoutered is inconvenient.
The USB issue is actually done for security reasons. For example, many large customers don't want users to have the ability to just walk up and plug in a USB device and allow the system to detect that and attempt to boot to it right away as it is a risk to their image/security. For this reason, USB devices don't automatically get added to the boot order, and must be added throught he setup menu if needed.

External USB Hard Drive causes menu problem - menu items flash

Greetings:
I have a external USB hard drive (250 GB) that is partitioned into 3 hard drives. Two hard drives are formatted in MacOS standard and one is formatted in MacOS extended. I had to reformat the last drive in MacOS extended because the Macbook would not let me edit files on the drive.
The problem is that when I connect to the drives, the menu malfunctions (I cannot see the date and time and the menu items flash). Dismounting the drives solves the problem.
Do I need to reformat the hard drives? Or do I need a new USB drive?
Thank you.
EA

Hmm, someone else had a similar problem. Note the ":: Loading root filesystem module...-e" line. That "-e" shouldn't be there. It should be, instead, the module for the filesystem.
As a workaround for right now, you can add your filesystem module to the MODULES array, and remove the "filesystems" hook.
In that case, you'll probably want rootdelay=* to allow the drive some time to settle, and rootfstype=* to speed up filesystem detection while in kinit.
By the way, what filesystem do you have on that machine? Can you tell me what
/usr/lib/klibc/bin/fstype < /dev/sda1
outputs on a running system (you may need to be root, or add yourself to the "disk" group or something similar) - /dev/sda1 should be replaced if the usb drive is not sda1

External USB hard drive won't reformat, won't appear in Finder, error: Unable to write to the last block of the device message

So I just got a new MacBook Air and since I had an external USB hard drive (TOSHIBA MQ01ABD100 1TB) lying around, I decided to use it for back-up. Since I only have just the one hard drive, I decided to partition it into two - one for Time Machine backups, and one for general files (formatted FAT so I could use it with Windows). However, the partitioning failed and I ended up with a partition named disk1s2. Plus, it won't appear on Finder anymore, but it appears in Disk Utility.
I have tried to reformat it, but I always get the message "Unable to write to the last block of the device".
Here's the info about my drive:
Name: TOSHIBA MQ01ABD100 Media
Type: Disk
Partition Map Scheme: GUID Partition Table
Disk Identifier: disk1
Media Name: TOSHIBA MQ01ABD100 Media
Media Type: Generic
Connection Bus: USB
USB Serial Number: 1220069C
Device Tree: IODeviceTree:/PCI0@0/XHC@14
Writable: Yes
Ejectable: Yes
Location: External
Total Capacity: 1 TB
Disk Number: 1
Partition Number: 0
S.M.A.R.T. Status: Not Supported
And here's for disk1s2:
Name: disk1s2
Type: Partition
Disk Identifier: disk1s2
Mount Point: Not mounted
File System: Mac OS Extended
Connection Bus: USB
Device Tree: IODeviceTree:/PCI0@0/XHC@14
Writable: Yes
Capacity: 999.86 GB
Owners Enabled: No
Can Turn Owners Off: Yes
Can Be Formatted: Yes
Bootable: Yes
Supports Journaling: Yes
Journaled: No
Disk Number: 1
Partition Number: 2
Here's what it says when I run diskutil in Terminal:
Device Identifier:        disk1
Device Node:              /dev/disk1
Part of Whole:            disk1
Device / Media Name:      TOSHIBA MQ01ABD100 Media
Volume Name:              Not applicable (no file system)
Mounted:                  Not applicable (no file system)
File System:              None
Content (IOContent):      GUID_partition_scheme
OS Can Be Installed:      No
Media Type:               Generic
Protocol:                 USB
SMART Status:             Not Supported
Total Size:               1.0 TB (1000204884480 Bytes) (exactly 1953525165 512-Byte-Units)
Volume Free Space:        Not applicable (no file system)
Device Block Size:        512 Bytes
Read-Only Media:          No
Read-Only Volume:         Not applicable (no file system)
Ejectable:                Yes
Whole:                    Yes
Internal:                 No
OS 9 Drivers:             No
Low Level Format:         Not supported
I didn't have any data in it prior to the failed partitioning attempt, so there aren't any worries of data recovery. But I'd really like to be able to use this drive again, and save some money (external hard drives are expensive where I live). Anyone with any ideas?

I'd also like to add that repairing the disk using Disk Utility does nothing but tell me to reformat the drive. So I'm stuck in a loop here.

Rescue and Recovery 4.3 on Win7 doesn't see a backup on external USB hard drive - Model W510

I've run the Rescue and Recovery utility within Windows 7 on two different external USB hard drives thinking that maybe it was a usb drive issue. When I open the R And R utility in expert mode I can see that both backups exist on their respective drives. I planned on updating my hard drive so I made a full hd backup and the R&R startup disc to boot the laptop from. The bios recognizes either external hard drive at boot with no problems. It shows the names and "+" sign next to drives. So I booted the drive at startup off the DVD drive with the R&R startup disc after I was sure that the bios recognized either external drives. Then when I choose a "Full" restore is of course asks me if I want to use hd, cd/dvd, or external usb drive which I choose the later. It then should show me the backup that I created earlier just as it did when I ran the utility from the Win7 environment so I can choose it to restore from. But I get a blank box showing no backups when I run the 4.3 R&R Startup disc. Again if I boot to Win7 and go into the R&R utility I can see the backup on the exact same USB external drive. Then boot off the CD startup recovery disc and it shows NO BACKUP! Help please! I want to shelf my old hard drive "as is" and create the Restore onto the new hard drive but the utility isn't working for me.
Thanks for any help.

Hmmm,
Seems like that _should_ work. Here's a way you might be able to finesse it: go to the advanced R&R menu in Win 7 and create rescue media on your USB drive. It's essentially the same process as creating the CD - it makes the USB drive bootable and puts a copy of R&R there.
There _should_ be an option to "preserve existing data" but be prepared to lose your existing backup and make it again.
Then just boot the external USB drive and see if R&R recognizes a backup image on the same drive from which you booted.
That's the way I usually migrate to new drives. Maybe it will get around your mysterious problem.
Z.
The large print: please read the Community Participation Rules before posting. Include as much information as possible: model, machine type, operating system, and a descriptive subject line. Do not include personal information: serial number, telephone number, email address, etc. The fine print: I do not work for, nor do I speak for Lenovo. Unsolicited private messages will be ignored. ... GeezBlog
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Transfering iTunes files to new computer using external USB hard drive

Thought this could be useful:
If you want to transfer your complete iTunes library to a new computer preserving all your playlists and library information, but without using your iPod as a hard dive, or without burning a CD or DVD, you can do it by using an USB external hard drive following these easy steps:
1) Quit iTunes
2) Connect your USB external hard drive to your computer and acccess it thru My PC or Windows Explorer.
3) Create two new folders in your external hard drive (you can name them LIBRARY Backup and PLAYLISTS Backup).
4) Open the LIBRARY Backup folder.
5) Open another Windows Explorer or My PC window; open the iTunes Music folder (usually located in C:\Documents and Settings\Owner\My documents\My music\iTunes).
6) Copy all of its contents (only the contents, not the whole folder) to the LIBRARY Backup folder you created in your external USB Hard Drive.
7) Close both the LIBRARY Backup folder from your USB external hard drive and the iTunes Music folder.
8) Open the PLAYLISTS Backup folder from your USB external hard drive
9) From your iTunes folder, copy the iTunes Music Library.xml to the PLAYLISTS Backup folder.
10) Close all the windows and extract your USB external hard drive from your PC ()
11) Install iTunes in your new computer.
12) Using Windows Explorer open the iTunes Music folder (usually located in C:\Documents and Settings\Owner\My documents\My music\iTunes).
13) Connect the USB hard drive to your new computer and open it using another Windows Explorer window.
14) Open the LIBRARY Backup folder and copy all of its contents (only the contents, not the whole folder) to the iTunes Music folder in your new computer. After the copying is complete, close this folder.
15) Copy the PLAYLISTS Backup folder to you new computer’s desktop.
16) Close Windows Explorer and extract USB hard drive.
17) Open iTunes
18) From the File menu, choose Import. Navigate to the iTunes Music Library.xml file on the Desktop and click Choose. The imported playlist will show only songs located on the computer's hard disk or external media.
19) You can now delete the xml. file from your new computer’s desktop if you wish.
PC Windows XP Owner of 5th Generation iPod

Type "move itunes library" into the Google search bar.
Type "ipod touch not recognized by itunes" into the search bar at the top of this page by "Support"

Unable to eject external USB hard drive

I've been using a 500 gb WD Passport external USB hard drive for about six months now, and recently it's had trouble ejecting. I'm not sure if it's the drive itself or my OS; sometimes I can eject it, other times I get the "the disk __ wasn't ejected because one or more programs may be using it.".
There are NO programs using the drive, and no users connected to the drive from elsewhere. Is there some process in the activity monitor that may be preventing the disk from unmounting?
I've tried to log out, relaunch the finder, quite all programs, etc - but the only sure fire method is to restart the computer - which leads me to believe there is some underlying system process that is causing the eject sequence to hang...
Any ideas? Will I potentially harm my disk's contents by force ejecting every time (so long as I'm certain no programs are writing files)?
Thanks!

I'm aslo having problems with a USB drive. In this case it's my Time Machine drive. Similar symptom that the only way to eject it is to restart the computer. Otherwise I get the same message. I also tried the Terminal command with the drag/return. What showed was an empty command line:
+ip-109-43-193-109:~ user$+
Now, the reason why I've even tried to do this is because I'm having problems backing up withTime Machine. Upon boot up, the first backup always works, but typically any subsequent b/up will fail with the following error code:
+Starting standard backup+
+Backing up to: /Volumes/Jimz TM 2/Backups.backupdb+
+Error: (22) setxattr for key:com.apple.backupd.ModelID path:/Volumes/Jimz TM 2/Backups.backupdb/user's MBP size:13+
+Error: (-50) Creating directory 2010-07-08-112436.inProgress+
+Failed to make snapshot container.+
+Error: (22) setxattr for key:com.apple.backupd.ModelID path:/Volumes/Jimz TM 2/Backups.backupdb/user's MBP size:13+
+Backup failed with error: 2+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
+Stopping backupd to allow ejection of backup destination disk!+
Also, this is the first time that I've seen the error lines regarding ejection of the disc.
Thanks in advance for any thoughts on this.

Can a la cie external USB hard drive be bootable on my G5?

Can a la cie external USB hard drive be bootable on my G5?

PPC Macs need a Firewire drive to boot from, IntelMacs can boot from USB, but Firewire drives with a one button touch feature won't work either, as examples...
The following external hard drives are bootable on Intel-based Macintosh computers systems through USB:
• My Book Essential Edition
• My Book Essential Edition 2.0
• My Book Home Edition
• My Book Mirror Edition
• My Book Office Edition
• My Book Premium Edition
• My Book Premium Edition II
• My Book Premium ES Edition
• My Book Pro Edition
• My Book Pro Edition II
• My Book Studio Edition
• My Book Studio Edition II
• My Passport Studio
The following external hard drives are bootable on Intel-based Macintosh computers systems through FireWire (1394a/b):
• My Book Home Edition
• My Book Mirror Edition
• My Book Office Edition
• My Book Premium Edition
• My Book Premium Edition II
• My Book Pro Edition
• My Book Pro Edition II
• My Book Studio Edition
• My Book Studio Edition II
• My Passport Studio
The following external hard drives are bootable on Power PC based Macintosh computers systems through FireWire (1394a/b):
• WD My Book Premium Edition
• WD My Book Pro Edition
The following external hard drives are not bootable on Power PC based Macintosh computers systems through USB/FireWire 1394(a/b):
• My Book Essential Edition
• My Book Essential Edition 2.0
• My Book Home Edition
• My Book Mirror Edition
• My Book Office Edition
• My Book Premium Edition II
• My Book Pro Edition II
• My Book Studio Edition
• My Book Studio Edition II
• My Passport Studio
• My Passport Elite
• My Passport Essential
• WD Passport
• WD Passport (Silver)
And I'm in no way suggesting a WD cased drive, there drives are good but the cases & chipsets leave much to be desired.

I put my macbook to sleep and unplugged my external USB hard drive, now It

does not show up on the desktop and can not be verified in Disk Utility. This is my first mac but have been running linux for a while now. Any help would be appreciated.

rustytiger wrote:
I put my macbook to sleep and unplugged my external USB hard drive, now it
does not show up on the desktop and can not be verified in Disk Utility. This is my first mac but have been running linux for a while now. Any help would be appreciated.
Well I hate to ask the silly question here but... did you plug the external hard drive back in?

Easiest Way to Backup Main Hard Drive to External USB Hard Drive

I was wondering what the easiest way is to backup my main internal hard drive to an external usb hard drive on a regular basis?
Thanks for the help

Carbon Copy Cloner is NOT "freeware":
http://www.bombich.com/software/ccc.html
The trouble with CCC and a USB drive, is that if you ever have trouble with your iBook's hard drive, you won't be able to boot from a USB drive to copy everything back with Carbon Copy Cloner.
I would recommend booting from the Mac OS X install DVD that came with your computer and opening the Disk Utility from the Utilities menu. There you can make a "restore" from your iBook's hard drive to the USB drive. If necessary, you can do the reverse as well.
-Doug

IMac is not detecting external USB hard drive

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