Update 1: Somehow, after ~ unconnecting and also re-connecting, the original disk (disk1) has actually now went back to original state, with the readme record as well! i still have one more disk i beg your pardon is not working. When associated to my MBP I get the message, "The decaying you placed was not readable through this computer." "".

You are watching: Unable to write to the last block of the device

Update 2:
Allan's question: Like exactly how long from once you to buy the drives and were functioning to when they stopped? Answer: castle were eliminated from the packaging on the job they arrived. These are brand new. Lock both settled of the box. Worries started after attempting to partition and also attempting to regain via Image.

Update 3: The disk at this time does not work-related on Mac or Windows. Next actions from here?


I bespeak two external hard disks and also tried castle on the an initial day they arrived. They appeared to occupational as a normal exterior hard drive when I first connected them to mine MBP (Retina mid-2015, Yosemite 10.10.3). However, after trying to partition/restore via disc Utility, they end up being both unusable. NB. One of them went back to original state — please see update 1, 2 and 3 above. So please additionally see mine attempts in ~ a systems in mine answer to this inquiry as recommend by

If these types of 2.5" external hard disks space actually not compatible with Macs or Time-Machine backups:

A) What deserve to I perform to return the disk earlier to its initial usable/exfat state?

B) In their original Exfat state, to what level will they it is in usable?

C) Why space they limited to Exfat format?

D) How, without the seller telling me, have the right to I recognize these are limited to Exfat format only? e.g. Are certain cheap 2.5" exterior HDDs from China always limited to Exfat?

Quick Intro: I very first tried to partition among them. This made that unusable. After ~ attempting to reclaim the an initial one by copying/cloning an image from the 2nd one, the second became unusable. Climate somehow the first disk randomly became usable again and was back to its original state (it even contained the original readme file).


I desire to perform a Time an equipment backup to an outside hard disk so ns bought 2 2.5” 2TB outside hard disks.

The tough disks (both identical) were described as compatible with macOS, both top top packaging and also on the digital description. I connected one of them for the very first time and also all looked normal. The only exception is that I uncovered a readme file, which discussed this drive can only it is in formatted come Exfat.

So my conclusion is that the journey is official in NTFS format, if the readme paper says it's Exfat only and the online description and packaging say's it's compatible v Macs. Ns contacted the seller, who replying saying that it doesn’t job-related with PS4 and is compatible through Windows, Mac, Xbox and Linux.

So after attempting come partition 1.1GB because that Time Machine, disc Utility gave me the article “Unable to write to last block the device”. In an effort to salvage the very first disk, I wanted to usually copy/clone the 2nd external drive in its original format and also burn the onto the an initial one the no much longer shows a volume. I plugged in the 2nd disk and also tried to usage the ‘Restore’ role via the reclaim tab and clicked on the ‘Image…’ button. Ns then obtained a blog post saying:

"Unable to create “JMicron generic Media1.dmg.” (Input/output error)."

The first screen shoot is what the difficult drive an initial looked prefer when associated to mine MBP. The second shows what it's like after it became unusable. Listed below that are display shots in chronological order, whilst attempting
Allan's suggestion.


Allan's advice i formatted the drive to Exfat ~ above Windows, back the "format walk not complete successfully". Top top Disk utility I now can see a greyed-out volume named Disk1s1. However, i still get the message, "The decaying you placed was no readable through this computer." "", once connecting to mine MBP. Moreover, the 'First Aid' option in Disk energy is greyed out.

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Now, diskutil list command result gives a volume kind of DOS_FAT_16. Compare this v the previous results that mirrors the initial (working) and previous (unusable) states.

The disk at this time does not work on Mac or Windows.Next actions from here?


Currently the decaying is unusable however with greyed-out disk1s1 in decaying utility. /dev/disk1 gives:

#: form NAME size IDENTIFIER 0: FDisk_partition_scheme *2.0 TB disk1 1: DOS_FAT_16 2.0 TB disk1s1sudo gpt -r -v display disk1 gives:

gpt show: disk1: mediasize=2000398934016; sectorsize=512; blocks=3907029168gpt show: can not to open an equipment 'disk1': Input/output errorsudo diskutil verifyDisk /dev/disk1 gives:

Unable come verify this entirety disk: A GUID Partition Table (GPT) partitioning system is compelled (-69773)diskutil details /dev/disk1 offers the following:

Nonexistent, unknown, or damaged partition map schemeIf you are sure this disk contains a (damaged) APM, MBR, or GPT partitionscheme, you might be able to repair it with "diskutil repairDisk /dev/disk1"diskutil repairDisk /dev/disk1

Nonexistent, unknown, or damaged partition map schemeIf you room sure this disk consists of a (damaged) APM, MBR, or GPT partition map,you deserve to hereby shot to fix it enough to be known as a map; another"diskutil repairDisk /dev/disk1" can then be necessary for additional repairsProceed? (y/N) yError repairing map: POSIX reports: Input/output error (5)diskutil partitionDisk disk2 1 GPT JHFS+ "Untitled" 100%

Started partitioning top top disk2Unmounting diskError: -69760: can not to create to the critical block the the deviceHere's what I've had actually a look in ~ (but not certain if it uses to mine case):

https://ipfs-sec.stackexchange.cloudflare-ipfs.com/apple/A/question/125965.html (I make the efforts diskutil eraseVolume exfat exfat2tb /dev/disk1 however got the following:

#: type NAME size IDENTIFIER 0: *2.0 TB disk1Originally (working disk):

#: form NAME size IDENTIFIER 0: FDisk_partition_scheme *2.0 TB disk1 1: Windows_NTFS 2.0 TB disk1s1