USB Drive Accidentally Unmounted & Now Won't Mount

Hi,
My Seagate 400 GB USB external drive was accidentally unmounted improperly and now it won't mount. I restarted my laptop, restarted the drive itself, changed cords and USB inputs on the laptop and nothing has changed.
The drive doesn't show up in Disk Utility, but it does in System profiler. In System Profiler it shows up, but with minimal information. My 300 GB Seagate drive (which is fine) shows up with a great deal more information like it's capacity etc. etc.
I have really essential information on the 400 including a project that's due relatively soon, so any help would me greatly appreciated!! THANKS!
-jules

Two things you can try:
Try connecting the drive, and restarting from the CD/DVD that came with your Powerbook, and use the Disk Utility to look for your connected drive.
You may also look in finder>preferences>general and make sure that the boxes are checked to show hard drives on the desktop.

Similar Messages

USB drives keep unmounting by themselves

This keeps happening over and over...
my USB drives are unmounting by themselves.
with no prompt or eject.
I've tried to re-set the PRAM. with no luck.
is this a on-going problem?
what can I do?

There are several reasons this might be happening so you'll need to provide us with more information.
1) are the drives connected directly to the computer or to a hub? If to a hub, try removing the hub and see if a drive or two connected directly to the computer will stay mounted.
2) who is the manufacturer of the drive(s)?
3) has this been an ongoing problem from day one or did it just recently start after a long period of stability? If the latter, did you make any changes about the same time the trouble began?

External Firewire drives power up, but won't mount.

I wanted to see if anyone else is having this problem. I recently upgraded my mom's laptop to OSX Lion after she experienced a lot of problems with Snow Leopard. All updates available from Software Update have been installed. Now 2 issues have arisen after the new install: 1) the FW 800 and 400 ports appear to be non-functional, and 2) the OS takes about 10 minutes to boot up to the desktop.
1) Regarding the FW ports: I have a couple external Firewire 800 hard drives that I use on other Macs so I know they're fully operational and mount without any issues. They're both 5400RPM drives that have been inserted into Macally external enclosures, and are of different capacities - one is 320GB and the other is 500GB. The enclosures offer FW 800, 400, USB 2.0 and mini-USB connectivity. But after upgrading the laptop I mentioned, neither of the drives will mount when using the FW 800 or 400 cables. They power up but won't mount, and they don't show up in the list in Disk Utility. However, the drives will power up and mount via USB.
I realize the laptop may have a hardware/port problem - but both 800 and 400 ports? Seems unlikely.
2) Any idea why it's taking the OS 10 minutes to boot up? I've shut down the laptop and rebooted it twice since the OS install, and both times took 10 minutes.
I may just install Lion on one of the hard drives, pull it and then pop it into the laptop to see if that makes any difference. Before I do that, can anyone recommend a hardware utility that can check the ports?
I welcome your suggestions.
Thank you.

Thanks for responding. Here's the info you requested. I'm not a systems guy so hopefully I've pasted in something that helps.
system.log report, after searching BOOT_TIME, here's one of the timestamps:
May 25 22:04:58 localhost bootlog[0]: BOOT_TIME 1337997898 0
Here's a chunk of the log after that timestamp:
May 25 22:05:00 localhost com.apple.launchd[1]: *** launchd[1] has started up. ***
May 25 22:05:13 localhost com.apple.launchd[1] (com.apple.powerd): Unknown value for key POSIXSpawnType: Interactive
May 25 22:05:13 localhost com.apple.launchd[1] (com.apple.sandboxd): Unknown value for key POSIXSpawnType: Interactive
May 25 22:05:18 localhost com.apple.pfctl[34]: No ALTQ support in kernel
May 25 22:05:18 localhost com.apple.pfctl[34]: ALTQ related functions disabled
May 25 22:05:18 localhost UserEventAgent[11]: starting CaptiveNetworkSupport as SystemEventAgent built May 25 2011 12:27:35
May 25 22:05:18 localhost UserEventAgent[11]: CaptiveNetworkSupport:CaptiveSCCopyWiFiDevices:388 WiFi Device Name == NULL
May 25 22:05:19 localhost com.apple.ucupdate.plist[28]: ucupdate: Checked 1 update, no match found.
May 25 22:06:14 localhost configd[14]: InterfaceNamer: timed out waiting for IOKit to quiesce
May 25 22:06:14 localhost configd[14]: Busy services :
May 25 22:06:14 localhost configd[14]:   MacBookPro3,1 [76967, 4375662836 ms]
May 25 22:06:15 localhost mDNSResponder[37]: mDNSResponder mDNSResponder-320.16 (Mar 17 2012 21:31:16) starting OSXVers 11
May 25 22:06:15 localhost com.apple.locationd[40]: ERROR,Time,359690775.485,Function,"_Apple80211* CLWifiService::createApple80211()",Apple80211GetIfListCopy failed, error -3903 (Unknown error: -3903)
May 25 22:06:15 localhost com.apple.locationd[40]: STACK,Time,359690775.485,1   locationd                           0x00000001077fe583 locationd + 624003
May 25 22:06:15 localhost com.apple.locationd[40]: STACK,Time,359690775.485,2   locationd                           0x00000001077fe719 locationd + 624409
May 25 22:06:15 localhost com.apple.locationd[40]: STACK,Time,359690775.485,3   libdispatch.dylib                   0x00007fff85f46c79 _dispatch_barrier_sync_f_invoke + 33
May 25 22:06:15 localhost com.apple.locationd[40]: STACK,Time,359690775.485,4   locationd                           0x00000001077fe9b0 locationd + 625072
May 25 22:06:15 localhost com.apple.locationd[40]: STACK,Time,359690775.485,5   locationd                           0x00000001077fea10 locationd + 625168
May 25 22:06:15 localhost com.apple.locationd[40]: STACK,Time,359690775.485,6   libsystem_c.dylib                   0x00007fff85e96e06 pthread_once + 86
May 25 22:06:15 localhost com.apple.locationd[40]: STACK,Time,359690775.485,7   locationd                           0x00000001077fea47 locationd + 625223
May 25 22:06:15 localhost com.apple.locationd[40]: STACK,Time,359690775.485,8   locationd                           0x00000001077f33ac locationd + 578476
May 25 22:06:15 localhost com.apple.locationd[40]: STACK,Time,359690775.485,9   locationd                           0x00000001077f353f locationd + 578879
May 25 22:06:15 localhost com.apple.locationd[40]: STACK,Time,359690775.485,10 libsystem_c.dylib                   0x00007fff85e96e06 pthread_once + 86
May 25 22:06:15 localhost com.apple.locationd[40]: STACK,Time,359690775.485,11 locationd                           0x00000001077f3509 locationd + 578825
May 25 22:06:15 localhost com.apple.locationd[40]: STACK,Time,359690775.485,12 locationd                           0x00000001077b052a locationd + 304426
May 25 22:06:15 localhost com.apple.locationd[40]: STACK,Time,359690775.485,13 locationd                           0x0000000107791653 locationd + 177747
May 25 22:06:15 localhost com.apple.locationd[40]: STACK,Time,359690775.485,14 locationd                           0x0000000107791a08 locationd + 178696
May 25 22:06:15 localhost com.apple.locationd[40]: STACK,Time,359690775.485,15 locationd                           0x00000001077921b2 locationd + 180658
May 25 22:06:15 localhost com.apple.locationd[40]: STACK,Time,359690775.485,16 locationd                           0x00000001077c332c locationd + 381740
May 25 22:06:15 localhost com.apple.locationd[40]: STACK,Time,359690775.485,17 locationd                           0x0000000107767fd8 locationd + 8152
May 25 22:06:15 localhost com.apple.locationd[40]: STACK,Time,359690775.485,18 ???                                 0x0000000000000001 0x0 + 1
May 25 22:06:15 localhost com.apple.usbmuxd[27]: usbmuxd-268.5 on Jan 5 2012 at 03:34:01, running 64 bit
May 25 22:06:15 localhost UserEventAgent[11]: CaptiveNetworkSupport:CaptiveSCCopyWiFiDevices:388 WiFi Device Name == NULL
May 25 22:06:15 localhost UserEventAgent[11]: ServermgrdRegistration cannot load config data
May 25 22:06:15 localhost UserEventAgent[11]: get_backup_share_points no AFP
May 25 22:06:15 localhost systemkeychain[59]: done file: /var/run/systemkeychaincheck.done
May 25 22:06:15 localhost configd[14]: ioctl(SIOCGIFCAP) failed: Device not configured
May 25 22:06:16: --- last message repeated 1 time ---
May 25 22:06:16 localhost mDNSResponder[37]: D2D_IPC: Loaded
May 25 22:06:16 localhost mDNSResponder[37]: D2DInitialize succeeded
If you want me to post the kernal log, I can do that next if nothing in here points anyone in the right direction. FYI - the system booted normally this morning after shutting it down overnight.

External HD Won't Mount - Force Ejected it and now won't mount

Hi All,
I seem to remember this happening to me before. Isn't there somewhere in the filesystem that OSX writes a file if a drive was mounted? And if you ejected a USB disk incorrectly, it cannot ever mount again?
I can't seem to find that fix anywhere.
ANYWAY, my problem is this. My TimeMachine backup disk (Western Digital (WD) 500 GB MyBook) won't mount (attached via USB). It doesn't show up in the Finder. It DOES show up in Disk Utility but when I click Repair Disk it promptly says:
"Error: Disk Utility can’t repair this disk. Back up as many of your files as possible, reformat the disk, and restore your backed-up files."
I really don't think the disk is fried. I think there is just something keeping it from being mounted. I could be wrong.
Any ideas? Thanks in advance. Struggling with this waaay too late on a Sunday night.
I'm running Snow Leopard 10.6 (10A421a)

Hi whatstin
See the lower part of > http://support.apple.com/kb/HT1317
+1. Shut down the computer.+
+2. Disconnect all devices and all other cables, except the keyboard and mouse cable(s).+
+3. Disconnect the computer from the power outlet and wait for 3 to 5 minutes.+
+4. Plug the computer back in and turn it on.+
+5. Reconnect the device(s) (one at a time if there is more than one) and test. Test with each port if you have more than one.+
If nothing then try a different USB cable.
If still nothing contact WD support @ http://support.wdc.com/?wdc_lang=en
Dennis

XserveRaid (14drive model): Left Side now won't mount?

I have a 14-drive Xserve RAID. It's been working flawlessly for at least two years. Today, I moved the rack across the room, to slightly redesign the office, and when I restarted it back up, the Left Side now will not mount.
It's full of drives, seven on each side. Raid 5. Connected to G5 PowerPC, with 10.5.6 installed.
The left side power light comes on, but after the right side boots and mounts as normal, the left side continues to show a constantly blinking light on the front, with the icon that appears to look like a "guitar head", or Fiber Channel icon. The other three indicator lights on the left side are also GREEN.
I disconnected the fiber channel cables from the back of the Xserve, and the left side fiber channel icon continues to blink.
The right side mounted just fine on the Desktop, as normal.
When I look at Fiber Channel control panel in 10.5.6 System Preferences, the Left Side shows red light and the Right Side shows green light. Red Light means disconnected.
Are there any other diagnostics that I can do today? Of course, I need to be working on files that are from the left side...
Here is a screengrab from the System Prefs:
http://199.237.236.200/temp/fiber.jpg
Thank you.
Mark Tucker
http://www.marktucker.com
mark at mark tucker Dot com
Message was edited by: Mark Tucker

Hi Mark
It's a good job you have a backup. It's even possible the controller might be failing? Perhaps the move is purely co-incidental? You could also swop the controllers to see if the problem follows the controller? Although I would leave off doing that just yet.
Reseating the controller is a useful thing to do as over time they can - sometimes - work themselves slightly loose. You've probably had the thing on 24/7 for 2 years so only a shutdown followed by a move could possibly make this apparent? If you search the forum you should find similar situations to yours.
Tony

TM Drive no icon and won't mount/unmount

I have a Glyph GT050Q firewire drive that I'm using as a Time Machine backup drive. I used to have a time capsule but it died suddenly (like others have complained about). Anyway I decided to abandon Time Capsule.
The drive is attached directly to the MacBook Pro.
It works as a backup drive fine, it's just that Time Machine doesn't mount/unmount the drive and when it's being used for backup it doesn't get the custom Time Machine backup drive blue icon.
Is there a way to get this to work? It didn't work under OS 10.5 and I was sure when I upgraded to OX 10.6 that it would fix itself, but no luck.
By the way I've already tried trashing the TimeMachine.plist, that didn't do anything.
Is it only the Time Capsule that can mount/unmount? It's not the biggest of deals to have it on the desktop all day except that the system and certain applications periodically scan all drives which prevents the drive from sleeping. I have Time Machine Editor v 2.5.3 set to backup up every 6 hours.
Thanks

bcoughlin wrote:
I have a Glyph GT050Q firewire drive that I'm using as a Time Machine backup drive. I used to have a time capsule but it died suddenly (like others have complained about). Anyway I decided to abandon Time Capsule.
You might qualify for a free replacement. Check this out: http://support.apple.com/kb/TS3351
It works as a backup drive fine, it's just that Time Machine doesn't mount/unmount the drive and when it's being used for backup it doesn't get the custom Time Machine backup drive blue icon.
That's correct; Time Machine doesn't mount and dismount directly-connected drives the way it does network drives. And it should have a green icon.
Is it only the Time Capsule that can mount/unmount? It's not the biggest of deals to have it on the desktop all day except that the system and certain applications periodically scan all drives which prevents the drive from sleeping.
That shouldn't be a problem. HDs are built to run 24/7.
I have Time Machine Editor v 2.5.3 set to backup up every 6 hours.
That's usually not a good idea, if you can avoid it. Local backups should be much faster than network, and won't be contending for your network connection. See #13 in Time Machine - Frequently Asked Questions (or use the link in *User Tips* at the top of this forum).

External Drives, CDs & Disk Images Won't Mount

I am having some weird issues with my G5. I recently did a fresh install of Leopard on a brand new hard drive and everything was running smoothly. I copied a bunch of settings from another drive to keep my information intact on the new install and I didn't notice any issues. I have now started to notice that after about a day of leaving the G5 on, it no longer mounts disk images, CDs or external hard drives OR if it does in fact mount them, it takes FOREVER to do so. This also causes Disk Utility and System Profiler to crash or take a long time to start.
I don't know if this helps at all, but two new hardware additions to the machine were an internal bluetooth adapter (for use with the new Magic Mouse) and more memory. Both have been working correctly so I don't know that either is the cause of this problem.
I've tried a bunch of random things to see if I can get something to work again - fixing permissions, verifying disks, etc., but the only thing that really works is a restart. Everything stops working again about a day after the restart though.
Has anyone else encountered this sort of problem, and if so, do you have any suggestions for how to fix it? Any help would be appreciated!

So I think I may have something to show from Console regarding an external drive that took forever to attach:
12/2/09 3:34:42 PM fseventsd[40] callback_client: ERROR: d2fcallbackrpc() => (ipc/send) timed out (268435460) for pid 387
12/2/09 3:34:42 PM fseventsd[40] client: 0x819000 : USER DROPPED EVENTS!
12/2/09 3:34:42 PM fseventsd[40] client: 0x819000 : USER DROPPED EVENTS!
12/2/09 3:34:52 PM fseventsd[40] callback_client: ERROR: d2fcallbackrpc() => (ipc/send) timed out (268435460) for pid 387
12/2/09 3:35:02 PM fseventsd[40] callback_client: ERROR: d2fcallbackrpc() => (ipc/send) timed out (268435460) for pid 387
12/2/09 3:35:02 PM fseventsd[40] callback_client: ERROR: d2fcallbackrpc() => (ipc/send) timed out (268435460) for pid 387
12/2/09 3:35:02 PM fseventsd[40] client: 0x819000 : USER DROPPED EVENTS!
12/2/09 3:35:02 PM fseventsd[40] client: 0x819000 : USER DROPPED EVENTS!
12/2/09 3:35:24 PM fseventsd[40] callback_client: ERROR: d2fcallbackrpc() => (ipc/send) timed out (268435460) for pid 181
12/2/09 3:35:24 PM fseventsd[40] client: 0x80ec00 : USER DROPPED EVENTS!
12/2/09 3:35:24 PM fseventsd[40] client: 0x80ec00 : USER DROPPED EVENTS!
12/2/09 3:35:34 PM fseventsd[40] callback_client: ERROR: d2fcallbackrpc() => (ipc/send) timed out (268435460) for pid 181
12/2/09 3:35:36 PM fseventsd[40] callback_client: ERROR: d2fcallbackrpc() => (ipc/send) timed out (268435460) for pid 379
12/2/09 3:35:36 PM fseventsd[40] callback_client: ERROR: d2fcallbackrpc() => (ipc/send) timed out (268435460) for pid 379
12/2/09 3:35:36 PM fseventsd[40] client: 0x81de00 : USER DROPPED EVENTS!
12/2/09 3:35:40 PM fseventsd[40] callback_client: ERROR: d2fcallbackrpc() => (ipc/send) timed out (268435460) for pid 18245
12/2/09 3:35:40 PM fseventsd[40] callback_client: ERROR: d2fcallbackrpc() => (ipc/send) timed out (268435460) for pid 18245
12/2/09 3:35:40 PM fseventsd[40] client: 0x81a000 : USER DROPPED EVENTS!
12/2/09 3:35:40 PM fseventsd[40] client: 0x81a000 : USER DROPPED EVENTS!
12/2/09 3:35:44 PM fseventsd[40] callback_client: ERROR: d2fcallbackrpc() => (ipc/send) timed out (268435460) for pid 181
12/2/09 3:35:44 PM fseventsd[40] client: 0x80ec00 : USER DROPPED EVENTS!
12/2/09 3:35:44 PM fseventsd[40] client: 0x80ec00 : USER DROPPED EVENTS!
12/2/09 3:35:50 PM fseventsd[40] callback_client: ERROR: d2fcallbackrpc() => (ipc/send) timed out (268435460) for pid 18245
12/2/09 3:36:00 PM fseventsd[40] client: 0x81a000 : USER DROPPED EVENTS!
Any clue as to what this is?

WD 500g fell down, now won't mount!

Hello everyone,
I don't know if this is the right place to be asking this, but its a start.
I have bought a WD 500g My Book pro, I have almost 350g of info on it. Yesterday, my wife tripped over the cord and it fell down on the floor.
Now, when I plug it in I get this error message:
"The disk you inserted was not readable by this computer"
Initialize.. Ignore .. or Eject
Ignore and eject nothing happens, when I hit initialize, it takes me to the disk utility.
I see the hard drive on the left panel named: "2.0 TB WD External Media"
Strangely, when I click on it it says: "2TB" as in 2 TeraByte of storage! Its suppose to be 500g, Only.
I know if I probably hit format, it will work again, but I really need the files on the Hard Disk. Is there anyway to get it to work?
PS. I tries Data Rescue II and Disk Warrior, nothing happened.
If anybody can help direct me to the solution or the right place to get help for this I would really appreciate it.
I can't take this to an APPLE store, I'm not in the states ATM.
Thank you in advance.

It would be best to find out first if the hard drive itself has been damaged. Typically inside those prepackaged Harddrive enclosures you will find a regular 3 1/2" harddrive, either ATA/100 or a SATA type. Sometimes you might find a 2.5" drive, but at 500GB, its probably a SATA 3 1/2" drive.
With any luck its just the enclosure itself that is damaged, and not the hard drive. Physical trauma such as the read/write head(s) smashing into the platters can happen after a fall.
First off, the easiest thing to try is a new USB cable. Its a small possibility, but should be tried.
Do you have access to any IT personnel? If you dangle a case of beer in front of them, maybe they can help with the diagnostics. He/she can remove the drive from the Western Digital enclosure and hook it up to another system to determine if its salvageable and maybe pull the data.
As far as a Linux install is concerned, various Distros offer a LiveCD/DVD option which is a complete operating system on CD/DVD with no need to install. Sabayon Linux offers a specialized LiveCD ISO for download, as does Ubuntu. Download the disc image, burn it, and boot the system from the CD/DVD.
I haven't tried it yet, but there is probably enough intelligence within the usb subsystem on the Ubuntu LiveCD for it to automatically detect the HFS+ partition on your Western Digital external box.
JeffEmbracedDC below mentions a Windows software that will allow you to read HFS/+ partitions. You could always give that a go.

USB drive started unmounting itself after OS X update

Has anyone a work around to get a USB hard drive to stop unmounting itself? The drive used to work flawlessly and only started behaving as though the cable were disconnected following an OS X update.

Don't know about the update as a possible cause, but WD externals have a reputation for being very flakey with Macs, or flakey period. You could try a PRAM reset: hold CMD-Option-P-R keys down together at the startup chime, keep holding down until you hear two more chimes, total three, then let go and it will finish booting.
Also, you might try re-applying the 10.5.8 Combo Update.
http://support.apple.com/downloads/MacOS_X_10_5_8_ComboUpdate

USB WD MyBook Home 1TB won't mount when plugged in to time capsule.

Basically what the subject said. The drive won't show up on the desktop, in the "TimeCapsule" icon in finder, or the Disk Utility, it does however show up in the AirPort Utility. The Airport Utility allows no settings to be changed for the drive. How do I use the drive. I can only figure one thing and it would be a long time to fix. The drive is formatted in NTFS. I have NTFS 3G, so it could only be the Time Capsule itself doesn't have the technology to handle it. Given it is an SAS Drive, it shouldn't have a problem mounting it.
P.S. No formatting please, I would rather not have the hard drive plugged in than lose the 5 Professional Premiere Pro projects saved on the drive. They span about 400GB with the captured footage and I don't have enough space on either of my other 1 TB drives (Time Capsule, and Internal WD Caviar Black) to back them up without deleting important data.

P.S. No formatting please, I would rather not have the hard drive plugged in than lose the 5 Professional Premiere Pro projects saved on the drive.
Probably best to not have the drive plugged in to the Time Capsule as it wants to see a drive formatted in Mac OS Extended (Journaled) or FAT 32.
Normally, with a FAT 32 or Mac OS drive, you would open Finder and click on the Time Capsule icon under the SHARED heading. When you click on the Time Capsule, the name of the drive will appear in the window to the right. Double click the drive to get it to mount on the desktop.

New ATA/IDE Drive - Mac OS X Won't Mount the Drive!

Hello out there!
I have a problem- I installed a new 80GB WD ATA drive to my old PM G3 - everything went in smoothly, hooked it up to the "Ultra ATA" slot on the motherboard, and booted. (It is now the only disk, set to Master - jumpers, not cable select)
The main objective is to get out of OS 8/9 and get into X. I put in the OS X install disc, and get all the way to "Select Destination" - the drive is no where to be seen.
I went into the installer logs, says that the drive didnt mount, and it tried again, then gave up.
I then went into Disk Utility, click on the Disk, saw the Volume didnt mount... Erased the Disk, to Mac OS X E - and it appeared to erase - but - still no mount...
I have erased the Disk too... still no mount, the computer clearly knows the disk is there, but wont mount the volume.
Never had a problem like this before, and you guys are so impressive!
Hope you can help me out!
Thanks!
Chris
PowerMacintosh G3, PowerBook G4 Mac OS X (10.4.7)

Without the 646U2-402 chip on your motherboard, you have the "Heartbreaker" Blue & White G3. When upgraded to a Hard Drive faster than the original 4, 6, or 8 GB drives that shipped with the units originally, they become flaky -- producing crashes, freeze ups, and eventually disk corruption. But never repeatable enough to diagnose a firm problem.
The solution for most users has been to install a PCI Hard drive Controller, IDE or SCSI at your option, and live happily ever after. (Recently, the cheapest Mac-specific IDE Controllers have been new at NewEgg.com. The cheapest bootable SCSI is the used Apple/ATTO UL2D).
"Happily Ever After" that is, until you try to transfer large amounts of data over FireWire. At which point you may be forced to install a controller for FireWire to get satisfaction in using that Bus. Oh, and the Blue & White can not share its drives over FireWire using FireWire Target Disk mode, either.

How to eject USB drive safely when it isn't mounted?

Hi,
I bought a USB 3.0 splitter on eBay and took it to the test. I put in four devices but only three of them showed up. I have tried to search a bit but I couldn't find any solution. As far as I know, the hard drive isn't mounted but it is running.
I have had this problem some time ago but I think I just pulled the drive out that time. I don't want to risk damaging the hard drive because it contains important data. This didn't happen before I (unfortunately) upgraded to Yosemite and have had some other faults too.
Does anyone of you know how to eject the hard disk properly?

If it’s not mounted, it can just be unplugged. To double-check, choose Utilities from the Finder’s Go menu; if all the volumes on a drive appear in gray in the sidebar, it can be safely unplugged. If the drive doesn’t appear at all, the computer doesn’t recognize that it’s connected, and it can be safely unplugged.
(120241)

External hard drive isn't visible, won't mount

Hi,
I have a WD MyBook external hard drive that is not working correctly with any mac. It randomly stopped showing up on the desktop or in the finder. I don't move it around at all, so I have no idea what the origin of the problem is. I have tried plugging it into a black Macbook, white Macbook and Macbook Pro with the same results. It shows up in both the System Profiler and Disk Utilities. In the System Profiler, I can get information on the drive. The only thing I see of note is that there isn't a mount point. In disk utilities the hard drive is gray. When I click on it to repair it, I can only repair or verify the disk. When I do that, it tells me that the drive "appears to be okay". I try to mount it and it tells me it cannot be mounted and to try running first aid. I also can't eject it.
I'm at a loss at this point. Is there something else I can try?
Thanks in advance for any suggestions and sorry for the long post!

Had the exact same problem yesterday and wanted to share how I solved it. It first happened a couple months ago. Would not mount on my Mac Pro, but it did show up when I connected it to my laptop. I solved it by just shutting off the Mac Pro, unplugging it even, and unplugging everything from the My Book drive. I let it sit for 3 hours. Started the Mac Pro up, then put FW cord into My Book, then into Mac Pro, then connected the power cord for the My Book. That worked. For some reason.
But I tried that again when My Book Pro Edition disappeared yesterday (could see it grayed out in Disk Utility, but it would not mount) and nothing would bring it back. After looking through the Western Digital site, I figured it had something to do with the partition being bad. I thought I'd have to buy Stellar Phoenix data recovery software, which might have recovered my data. But first I went out and bought Disk Warrior. Disk Warrior fixed it! I'm back up and running.
My theory on why My Book Pro Edition had problems this second time. To save my on my electric bill I write this during the recession), every night after I shut down the Mac Pro, I also turn off the power strip. Cutting the cost of "vampire" electricity, as they say. Now I see I wasn't shutting down the My Book properly... you need to follow the Safe Shutdown instructions -- pressing Power Button once. Although I also have the My Book Studio connected which hasn't been affected by my turning off the power strip as it seem to shut off by itself when the Mac Pro is shut down. I think improperly shutting down the My Book Pro every night is likely the reason Disk Warrior diagnosed the problem as a "severely damaged directory."

LaCie external drive - one partition suddenly won't mount

I recently moved my itunes library over to my external 160gb harddrive - I put the itunes library on one of two partitions. After my computer froze up and I had to force it to restart, only the second partition shows up. In disk utility, the first partition is greyed. It will not mount, and when I attempted to repair it, I got a message saying "the underlying task reported failure on exit."
After reading post after post I'm starting to think I'm looking at a new harddrive. The data on the second (working) partition is very valuable to me, so I want to do something that will overhaul the whole drive. The missing partition contains music which is safely on my ipod, so I'm less concerned about that.
Any suggestions on how to either access the greyed partition or in setting up a new system would be greatly appreciated.
Thanks!

Hi,
Welcome to the Discussions.
When a drive isn't unmounted prior to disconnecting or shutting down (as a forced shutdown will do) the drive's directory can become corrupted. The error message Disk Utility gave you indicates the directory on that partition is damaged. Disk Warrior can repair most types of directory damage with no data lost.
John

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