Partition failed couldnt unmount disk mac

With the help of Disk Utility you can fix damaged file system and corrupted data structure. But in case if you can not solve the problem, then the only option left for the disk repair that failed with the error could not dismount the disk , is to format the entire Mac hard disk.

Formatting the entire disk can Easily remove all problems behind the occurrence of this same error on your Mac system. However, it will also cause the removal of all important files from the entire disk drive but it will solve the problem completely as well. You can recover all your important files once the disk repair that failed with the error could not be dismounted the disk will be completely fixed on your system.

Fortunately Mac Data Recovery Software is there to recover all the lost after any kind of critical data loss situation. You can easily recover lost, deleted, formatted or inaccessible files in Mac OS. Therefore, it is recommended to use the Mac data recovery software to recover all files formatted disk and repair the error was not able to unmount the disk. Although Mac OS X is fairly reliable, but still not free from glitches.

Finally, as a result, the Mac system can not process your entire request and can crash. Inconsistencies related to the Mac OS X file system can lead to data corruption so it is completely inaccessible.

How to deal with “Couldn’t Unmount Disk” error

The downloading of applications and other related files will lead to the security issue, which further influence the entire file system. All of the reasons mentioned above are the likely causes of inaccessibility of mac data. Well, for its viability here are some of the common symptoms. There is a well known proverb that caution is better than cure, this is also applicable in the case of Mac data. But why do it! If here is an effective solution for it.

Even the slightest mistake could bring risks to the data. Undoubtedly, Mac data recovery software is a very simple and reliable tool that rescues the data in case of your loss. It has also been noted that, the tool is very effective in all cases of non-data loss situation, regardless of the reasons behind the problems of corruption or elimination. Apart from that, its robust recovery algorithm performs the complete scan of all Mac hard drives either its internal or external and provide users with optimum results.

Another feature of this same software is that it can be easily installed and operated with minimal use of system resources. In addition, due to all these efficiency and meritorious work in the field of data recovery, the tool has won 8 of the 10 awards worldwide. Do not delay any longer, there is nothing as good as Mac data recovery software. Enabled with advanced built-in record search and retrieval features in one click. I do not have any Time Machine backups.

Everything came out of file, but in the middle of the installation, it got stuck, and later the error in the installation, for no reason.


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  • 3 Ways to Fix ‘Couldn’t Unmount Disk’ Error!

So, I tried to reboot again, but was told that the reinstallation failed and asked me to reinstall again. I tried to reinstall, but found nothing. So I tried to use the Disk Utility to erase the boot disk and make a new partition. But, when it comes to the partition, the Disk Utility said that you can not unmount the disk. As far as I know, I do not see that disk2 on my disk list before. So I tried to use the Terminal to force disassemble the disk, but it still would not let me. Is that disk2 the reason why I can not main partition my HD?

I already have a boot image on my USB drive. I just can not start because of the installation fails and something is still running I guess. I just can not boot because of the installation fails and something is still running I guess. Screenshot of Disk Utility:. The Mac OS X core system image is not the cause of your problem. To get an explanation. My best guess, based on the screenshot, as to why it can not re-create partitions of the Hitachi disk is that it is the current boot device. You can boot from the recovery partition leaving the alt pressed when you turn on the computer, you should leave the normal partition and the recovery, enter the recovery to see if from there you leave.

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You enter the recovery and reinstall the flip lion. Do not forget once you have booted, enter the disk utilities and delete the installation partition, so that everything is done from scratch. Thank you. But that of disk utilities and delete the hdd partition I do before installing mac osx lion no? Good morning I had formatted an imac, I bought one of segundamano and I want to leave it empty. But following the internet instructions I get that error when deleting the disk. This is an imac of I wanted for another room and use it to navigate, it is not new.

I have read that to do a formatting from 0 I must do it from an external HD, but I do not know what I should do to get to that step, what should I install to that external disk before? Greetings and thanks. I am trying to restore the hard disk because bootcamp asks me but the disk utility gives me error when dismounting the disk. It does not let me dismount from disk utility starting with the windows install partition.

Lol thanks. You can not unmount a disc that is in use. Of course, you can not do that with the normal computer started. You have to boot from the installation DVD or the Lion recovery partition the latter only if you use Lion. I want to format mountain lion, I do what should be done, I use disk drives, I give it to erase but it tells me that there has been an error and that you can not unmount the disk, what can I do? I bought a snow leopard installation disk, which is the system that came when I bought the mac, will it work? Ie, disk utility resides on the same disk that you try to format?

If so, there is the problem. You can not erase a disc using a program that is on the same disc. It is as if a crane is trying to lift itself. To format the disk, boot from the Snow Leopard disk. The disk is Gb SSD. How long should I leave the command running?

I left it all night and got the same result. I was setting up a usb Yosemite boot drive but it hanged upgrading from Snow Leopard to Yosemite. Had issues reformatting the USB to restart the process. I would get the same message: sh I had hard disk errors so i ordered a new one. I read about your solution above, but wondering if it would work on the internal SATA hard drive. I also tried to create a new partition, but it fails too. What model and vintage Mac are you working with?

Since you can boot from a thumb drive, your computer will apparently work from an external drive. I use one from time to time for testing drives. If you are going to end up getting a new computer, the USB 3 model will be sufficient. If your computer is failing no replacement drive is likely to work. You can use any of the drive adaptors for this, though an external drive in a case is probably a better way to go if you intend to continue using the computer for any length of time. Thank you for writing this article.

Recently I upgraded to Yosemite. After few successful back-ups, I decided to encrypt back up. Encryption was going on fine, when suddenly on 3rd day, my MCB mid started ejecting My Book after few minutes. After this I tried many things and I think I ended up making it worse. Resource busy This error came during partition after following the steps or Unable to write to the last block of the device.

Thank you! This has helped keep my mental sanity on numerous occasions with corrupted drives. Hi and good day, im having a similar issue with my pendrive. Password: sh Brilliant solution! Running the script, rebooting and then formatting the external hard drive worked for me. Just wanted to say thank you dude! I sure would appreciate any help someone may have. Thank you. Hi Brad.

How to Fix "Couldn't Unmount Disk" Error

Have you restarted your Mac with the drive connected? Often when the system sees a drive it cannot recognize it will offer to format it. Does Disk Utility recognize the disk? If so, will it mount when you click the Mount button in the toolbar? Disk utility does recognize but will not allow mount. I tried to mount it in terminal. It said it mounded but did not show that in diskutil. After doing some research on line I found that the USB flash drive I had purchased was a counterfeit drive. When plugged in it read in disk utility 1TB but would not support the data.

It would load the initial folders and the first few would be good, but the rest would be empty. Why does disk utility show an incorrect amount of storage and is there a way to ascertain the correct storage other then just dropping data on it? Worked the first time and I found this article at the last minute before giving up. Thank you again! As others have said, thanks for all your guidance and congratulations to those who have used it successfully.

Unfortunately, in my case, after following all possible avenues covered in the multitude of ideas here, my situation remains that I have an external Seagate HDD, 1TB FreeAgent GoFlex that no longer works. The current situation is thus:. On the right hand side, First Aid is all grayed out, but Erase is operational.


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  6. So, I try to erase with the default options, i. I guess that gives me another path to investigate but if you have any new advice to offer, I would be very grateful. Larry, rather than trying to erase the drive, reformat it instead. Let us know if this works.

    Hi, Jefferson, this is something I have tried, multiple times. Trying again, this is what happens:. I connected the USB drive to my MacBook Pro, the activity light came on and, after some seconds, started blinking indicating at least communication with the Mac. When I selected Initialize, that window disappeared, the activity light dimmed a bit, the drive disappeared from the DU left hand pane for quite some time but eventually reappeared but still only one line, the name 1 TB SeagateUSB 3. Nothing worked, hence my request for assistance. I know the easiest thing to do is to simply trash the drive but I hate to do that if there is any chance at all of retrieving it.

    If it were a smaller drive I might relent but 1 TB is too big to not at least try everything possible before admitting defeat which is something I hate to do. Hi Larry. One more thing to try: Before partitioning the drive, try using Disk Utility to unmount it not eject. If this works it should solve the disk is busy problem. DU will try to unmount it in any case in order to partition it. Another possibility: Boot in recovery mode and see if Disk Utility can handle the drive from there. If DU can see the disk, it will still be unmounted and should not be seen as busy.

    Trying to select anything other than Current in the Partition Layout is impossible. Checking the Erase tab shows everything all grayed out. You did find some interesting facts, however.

    How to Fix "Couldn't Unmount Disk" Error

    Two, that the drive is supposedly almost full. And three, that it appears to contain an OS X base system, which is usually just an invisible boot partition or in some cases can refer to an OS X recovery HD partition. Still, obviously, the drive in non-functional. Do you have access to DiskWarrior?

    Thanks for all your help. I thought you might have a friend who has it if you do not, in which case you could check the drive without cost. The other reason you might want to get DW is if the data on the drive is important enough to justify the expense. However, from you previous posts the drive does seem to be hosed.

    Partition failed couldn’t unmount disk

    I was able to run. Hot damn! It worked! I followed your thorough instructions and bam, they worked! Eventually Terminal showed binary garbage.

    How to use, troubleshoot, and repair your Mac

    I was able to run first-aid is disk utility and then format the sd card. That was a nightmare. You can delete the partitions on the drive there very quickly, and then reconnect it to your Mac for reformatting there. This post has got to be one of the dumbest tech suggestions I have ever read. Why not just wave a rubber chicken over the flash drive too. Perhaps typing insults is the limit of your skill set and actually using a complex process like this one is beyond even your imagination.

    In any case, you never get a second chance to make a good first impression—which is to say, you blew it. Did that, and a couple of seconds into it the device was unreadable and unusable. Took me a considerable amount of time and searching to figure out how to get it back to a state where I could even try to reformat it, and this particular post actually worked although trust me, the Windows way is MUCH faster and easier.

    But it certainly had sufficient detail to get my drive working again, without having to incur the cost of an RMA. If you have a better way, or constructive solution of your own, by all means please share it so others can benefit. So when you tried to encrypt it on the Mac the encryption failed and hosed the drive. If you used Western Digital software to try to encrypt the drive, it too should have warned you.

    If you got no such warning then perhaps I am mistaken about the origin of the problem. If you want or need to use a drive on multiple platforms, the Mac as well as Windows can read and write to a FAT32 drive, which is sufficient for all but the largest thumb drives. Of course, a FAT32 drive will not hold a bootable Mac system. But for data transfer purposes, it works just fine.

    A nightmare. Too much of their own garbage. A reboot froze half-way through. When I finally was able to boot, the WD drive had disappeared. Along with all of the icons for the apps in the dock, and half of them failed to appear. The generic Mac icon for apps was all that was left. Somehow, I was able to get DiskWarrior to recognize it as an unmounted drive and I installed a new directory. I rebooted, reset the PRAM, and the drive appeared.

    This time, reformatting by the Mac worked. But the blinking white light is so bright I have placed a strip of tape over it. So far, it has not failed, but searching the net, I found hundreds of complaints about my drive and yours. Now, to restoring all of the icons and the contents of the dock. Tried booting from other drive and running a couple of programs, but no good.

    DiskWarrior advised no replacement directory was required. Replaced it anyway. Rebooted to the internal drive and ran Onyx. After running the services and cleaning the surplus logs and rebooting, all the icons returned, the dock was fine, and so far, so good. Going back to the Mac towers, I always ran at least five drives in the tower. Two drives failed over the couple of years I used the Both were WD.

    The only brand that has ever failed since my first Mac in It appears that your system caches got corrupted at some point. How a new drive could have done that is a mystery—unless there was some malware on the drive. Not much of that around for the Mac, though. Anyway, once again, DiskWarrior to the rescue. A few people posting here think DW is a waste of money.

    And it may be—until you need it. The current version comes on a thumb drive with a utility that will put it on another thumb drive with your current base system. The drive DW comes on will boot older Macs, including PPC models, so creating an emergency disk for your current system is a good idea.

    Possibly so. After the reboot, I then boot from one of my external drives and run DiskWarrior, replace the directory, then go back to work after a second boot. Never can understand while people do not maintain at least one bootable external drive and consider DiskWarrior to be useless. Since I do always have at least two mirrored backups not counting two current full disk images auto backed up by SuperDuper scripting , I guess I take more chances than most.

    Getting ready to install Sierra. Hi Lloyd: Typos are par for the course. So having more than one tool in the box can be important. I use iDefrag for drive optimization. Results like these, therefor, seem a bit random. Obviously they are, as you report. But how did a new drive hose your system? Particularly as your system is so well maintained? Did you in fact reformat the drive before trying to encrypt it?

    Was it a GUID volume to begin with? If the cause of your problem can be diagnosed, it will make it easier to avoid it in the future. A long time to reply, but when someone assumes that the person they are responding to is pretty much a dullard and finally do end up replying. A small, bus-powered external drive did not do the harm. The trashy software that came with it, as many others attest, should simply be overwritten and forgotten.

    The WD 3 GIG drive that has been written about is advertised that it is for Mac, so it would be pretty weak to argue that it might have been formatted FAT 32, particularly when WD advises the purchaser that if they wish, the purchaser can reformat for Windows use. Reformatting or erasing using Disk Utility was no longer possible. Your fix has saved me! Worked swell! Tim: Not that it will help you now, but yes, you did it wrong. One partition is the right term for a drive formatted with one partition. That is the element you should have erased, to any of several levels of security available in Disk Utility.

    You can also just reformat a drive from the top level hardware name; that will erase the file catalog that keeps track of the data. To be thorough you can repartition a drive after you have erased it. Erasing the drive as you did removed the partition from the drive. Lacking a partition it would naturally be unmountable, though Disk Utility should still be able to see it for the purposes of applying a partition scheme to it.

    In this case the problem seems to be more severe for some reason—perhaps the age of the drive has something to do with it. This suggests to me that the drive may have been on the verge of failing in the first place, and what you did merely uncovered the hidden problem. Drives will often limp along in use showing no obvious signs of trouble even when trouble is lurking. Smart checking a drive—checking various drive parameters—with a utility like TechTool Pro can expose hidden problems, though sometimes even this is not enough. Disk Utility routinely does a smart check on a drive when you launch the app.

    But all it does is say pass or fail. To complicate things, there are also different kinds of smart check. Some utilities do a more thorough job than others. Disk Utility is fairly rudimentary. In some cases external drives cannot be smart checked at all so you can be flying blind.