I seem to have wrecked an external Sandisk SSD drive experimenting with File
Vault, at least so far as my iMac is concerned. It seems to sort of mount but cannot be ejected. Nor can Disk Utility do anything with it - it just locks up. And I cannot eject it.
It is formatted APFS, so AIUI Disk Warrior cannot handle it.
Is there any app that might possibly rescue it, or is it likely to be effectively a brick? Obviously any rescue would have to cost less than the value of the drive!
I have no need to rescue any of the content, just to erase and reformat the drive.
I seem to have wrecked an external Sandisk SSD drive experimenting with File Vault, at least so far as my iMac is concerned. It seems to sort of mount but cannot be ejected. Nor can Disk Utility do anything with it - it just locks up. And I cannot eject it.
It is formatted APFS, so AIUI Disk Warrior cannot handle it.
Is there any app that might possibly rescue it, or is it likely to be effectively a brick? Obviously any rescue would have to cost less than the value of the drive!
I have no need to rescue any of the content, just to erase and reformat the drive.
I seem to have wrecked an external Sandisk SSD drive experimenting with File Vault, at least so far as my iMac is concerned. It seems to sort of mount but cannot be ejected. Nor can Disk Utility do anything with it - it just locks up. And I cannot eject it.
It is formatted APFS, so AIUI Disk Warrior cannot handle it.
Is there any app that might possibly rescue it, or is it likely to be effectively a brick? Obviously any rescue would have to cost less than the value of the drive!
I have no need to rescue any of the content, just to erase and reformat the drive.
On 2024-06-12, Jaimie Vandenbergh <jaimie@usually.sessile.org> wrote:
On 12 Jun 2024 at 10:08:17 BST, "John Hill" <watcombeman@yahoo.co.uk>
wrote:
I seem to have wrecked an external Sandisk SSD drive experimenting with File
Vault, at least so far as my iMac is concerned. It seems to sort of mount but
cannot be ejected. Nor can Disk Utility do anything with it - it just locks >>> up. And I cannot eject it.
It is formatted APFS, so AIUI Disk Warrior cannot handle it.
Is there any app that might possibly rescue it, or is it likely to be
effectively a brick? Obviously any rescue would have to cost less than the >>> value of the drive!
I have no need to rescue any of the content, just to erase and reformat the >>> drive.
Wanging it into a PC (Windows or Linux) and doing it there, in an OS
that doesn't comprehend Apple filesystems at all and won't get all
wedged up trying to mount them, would be an easy way - if you have
access to one.
Yep saves messing with the CLI as per my OTT suggestion! Would that work with a Window$ or Linux VM running on a Mac?
On 12 Jun 2024 at 10:08:17 BST, "John Hill" <watcombeman@yahoo.co.uk>
wrote:
I seem to have wrecked an external Sandisk SSD drive experimenting with File
Vault, at least so far as my iMac is concerned. It seems to sort of mount but
cannot be ejected. Nor can Disk Utility do anything with it - it just locks >> up. And I cannot eject it.
It is formatted APFS, so AIUI Disk Warrior cannot handle it.
Is there any app that might possibly rescue it, or is it likely to be
effectively a brick? Obviously any rescue would have to cost less than the >> value of the drive!
I have no need to rescue any of the content, just to erase and reformat the >> drive.
Wanging it into a PC (Windows or Linux) and doing it there, in an OS
that doesn't comprehend Apple filesystems at all and won't get all
wedged up trying to mount them, would be an easy way - if you have
access to one.
On 2024-06-12, John Hill <watcombeman@yahoo.co.uk> wrote:
I seem to have wrecked an external Sandisk SSD drive experimenting with File
Vault, at least so far as my iMac is concerned. It seems to sort of mount but
cannot be ejected. Nor can Disk Utility do anything with it - it just locks up. And I cannot eject it.
It is formatted APFS, so AIUI Disk Warrior cannot handle it.
Is there any app that might possibly rescue it, or is it likely to be effectively a brick? Obviously any rescue would have to cost less than the value of the drive!
I have no need to rescue any of the content, just to erase and reformat the drive.
I've occasionally had problems with DU being unable to erase drives. I've found
that using the command line sometimes, but only sometimes, works.
Assuming the drive mounts OK, use 'diskutil list' to get its drive number. Then
use 'sudo diskutil eraseDisk APFS Untitled diskn' to erase it, where 'Untitled' is the
volume name which you can set as you wish of course. Replace 'n' with the number
shown in the 'diskutil list' command. Be very, very careful to get the value of 'n'
correct or you could have a disaster!
Alan B <alanrichardbarker@gmail.com.invalid> wrote:
On 2024-06-12, John Hill <watcombeman@yahoo.co.uk> wrote:
I seem to have wrecked an external Sandisk SSD drive experimenting with File
Vault, at least so far as my iMac is concerned. It seems to sort of mount but
cannot be ejected. Nor can Disk Utility do anything with it - it just locks >>> up. And I cannot eject it.
It is formatted APFS, so AIUI Disk Warrior cannot handle it.
Is there any app that might possibly rescue it, or is it likely to be
effectively a brick? Obviously any rescue would have to cost less than the >>> value of the drive!
I have no need to rescue any of the content, just to erase and reformat the >>> drive.
I've occasionally had problems with DU being unable to erase drives. I've found
that using the command line sometimes, but only sometimes, works.
Assuming the drive mounts OK, use 'diskutil list' to get its drive number. Then
use 'sudo diskutil eraseDisk APFS Untitled diskn' to erase it, where 'Untitled' is the
volume name which you can set as you wish of course. Replace 'n' with the number
shown in the 'diskutil list' command. Be very, very careful to get the value of 'n'
correct or you could have a disaster!
A cruder approach is just to nuke everything on it, not even using diskutil.
Run 'diskutil list' to get the drive number as above. eg 'disk2'.
It will definitely not be disk0 (that's your internal SSD) and perhaps not disk1.
Then run:
sudo dd if=/dev/zero of=/dev/rdisk2 bs=104857600
It'll take a long time (maybe hours) but you'll have a completely zeroed out device, no volumes, no APFS, no partitions, nothing. You can then try to
set it up from scratch again.
If you want a progress report while dd is running, press Ctrl-T in the terminal window.
Theo <theom+news@chiark.greenend.org.uk> wrote:
If you want a progress report while dd is running, press Ctrl-T in the terminal window.
Or add status=progress to the command maybe?
I seem to have wrecked an external Sandisk SSD drive experimenting with File Vault, at least so far as my iMac is concerned.
Alan B <alanrichardbarker@gmail.com.invalid> wrote:
On 2024-06-12, John Hill <watcombeman@yahoo.co.uk> wrote:
I seem to have wrecked an external Sandisk SSD drive experimenting with File
Vault, at least so far as my iMac is concerned. It seems to sort of mount but
cannot be ejected. Nor can Disk Utility do anything with it - it just locks >>> up. And I cannot eject it.
It is formatted APFS, so AIUI Disk Warrior cannot handle it.
Is there any app that might possibly rescue it, or is it likely to be
effectively a brick? Obviously any rescue would have to cost less than the >>> value of the drive!
I have no need to rescue any of the content, just to erase and reformat the >>> drive.
I've occasionally had problems with DU being unable to erase drives. I've found
that using the command line sometimes, but only sometimes, works.
Assuming the drive mounts OK, use 'diskutil list' to get its drive number. Then
use 'sudo diskutil eraseDisk APFS Untitled diskn' to erase it, where
'Untitled' is the
volume name which you can set as you wish of course. Replace 'n' with the
number
shown in the 'diskutil list' command. Be very, very careful to get the value >> of 'n'
correct or you could have a disaster!
A cruder approach is just to nuke everything on it, not even using diskutil.
Run 'diskutil list' to get the drive number as above. eg 'disk2'.
It will definitely not be disk0 (that's your internal SSD) and perhaps not disk1.
Then run:
sudo dd if=/dev/zero of=/dev/rdisk2 bs=104857600
It'll take a long time (maybe hours) but you'll have a completely zeroed out device, no volumes, no APFS, no partitions, nothing. You can then try to
set it up from scratch again.
If you want a progress report while dd is running, press Ctrl-T in the terminal window.
Theo
On 12 Jun 2024 at 14:04:41 BST, "Theo" <theom+news@chiark.greenend.org.uk> wrote:
Alan B <alanrichardbarker@gmail.com.invalid> wrote:
On 2024-06-12, John Hill <watcombeman@yahoo.co.uk> wrote:
I seem to have wrecked an external Sandisk SSD drive experimenting with File
Vault, at least so far as my iMac is concerned. It seems to sort of mount but
cannot be ejected. Nor can Disk Utility do anything with it - it just locks
up. And I cannot eject it.
It is formatted APFS, so AIUI Disk Warrior cannot handle it.
Is there any app that might possibly rescue it, or is it likely to be
effectively a brick? Obviously any rescue would have to cost less than the >>>> value of the drive!
I have no need to rescue any of the content, just to erase and reformat the
drive.
I've occasionally had problems with DU being unable to erase drives. I've found
that using the command line sometimes, but only sometimes, works.
Assuming the drive mounts OK, use 'diskutil list' to get its drive number. Then
use 'sudo diskutil eraseDisk APFS Untitled diskn' to erase it, where
'Untitled' is the
volume name which you can set as you wish of course. Replace 'n' with the >>> number
shown in the 'diskutil list' command. Be very, very careful to get the value
of 'n'
correct or you could have a disaster!
A cruder approach is just to nuke everything on it, not even using diskutil. >>
Run 'diskutil list' to get the drive number as above. eg 'disk2'.
It will definitely not be disk0 (that's your internal SSD) and perhaps not >> disk1.
Then run:
sudo dd if=/dev/zero of=/dev/rdisk2 bs=104857600
It'll take a long time (maybe hours) but you'll have a completely zeroed out >> device, no volumes, no APFS, no partitions, nothing. You can then try to
set it up from scratch again.
If you want a progress report while dd is running, press Ctrl-T in the
terminal window.
Theo
I tried Alan B's suggestion and it ran OK. But…
A bit of explanation.
The disk was originally a 1TB drive, divided into two equal separate containers. OK, not a good idea in retrospect. But what's done, is done.
One of these was used to hold a bootable system, generated by the system recovery mechanism, and on which the Data drive was kept up to date by Carbon Copy Cloner at regular intervals. The System drive was updated by booting from
it and using Software Update. All perfectly standard.
The other was partitioned into two by the approved Disk Utility method and each held a CCC copy of my data disk, updated on alternate weeks.
Alan's technique produced a single volume - but it was only 500GB. It looks as
though one of the two containers has been obliterated. So I thought that I would try Theo's method, to see if it would recover the whole space.
But when I tried it, I got the response "dd: /dev/rdisk2: Resource busy".
On 13 Jun 2024 at 12:46:33 BST, "Alan B" <alanrichardbarker@gmail.com.invalid>
wrote:
On 2024-06-13, John Hill <watcombeman@yahoo.co.uk> wrote:
On 12 Jun 2024 at 14:04:41 BST, "Theo" <theom+news@chiark.greenend.org.uk> >>> wrote:It needs to be unmounted -> 'diskutil unmountDisk disk2' ought to do that, then
Alan B <alanrichardbarker@gmail.com.invalid> wrote:
On 2024-06-12, John Hill <watcombeman@yahoo.co.uk> wrote:
I seem to have wrecked an external Sandisk SSD drive experimenting with File
Vault, at least so far as my iMac is concerned. It seems to sort of mount but
cannot be ejected. Nor can Disk Utility do anything with it - it just locks
up. And I cannot eject it.
It is formatted APFS, so AIUI Disk Warrior cannot handle it.
Is there any app that might possibly rescue it, or is it likely to be >>>>>> effectively a brick? Obviously any rescue would have to cost less than the
value of the drive!
I have no need to rescue any of the content, just to erase and reformat the
drive.
I've occasionally had problems with DU being unable to erase drives. I've found
that using the command line sometimes, but only sometimes, works.
Assuming the drive mounts OK, use 'diskutil list' to get its drive number. Then
use 'sudo diskutil eraseDisk APFS Untitled diskn' to erase it, where >>>>> 'Untitled' is the
volume name which you can set as you wish of course. Replace 'n' with the >>>>> number
shown in the 'diskutil list' command. Be very, very careful to get the value
of 'n'
correct or you could have a disaster!
A cruder approach is just to nuke everything on it, not even using diskutil.
Run 'diskutil list' to get the drive number as above. eg 'disk2'.
It will definitely not be disk0 (that's your internal SSD) and perhaps not >>>> disk1.
Then run:
sudo dd if=/dev/zero of=/dev/rdisk2 bs=104857600
It'll take a long time (maybe hours) but you'll have a completely zeroed out
device, no volumes, no APFS, no partitions, nothing. You can then try to >>>> set it up from scratch again.
If you want a progress report while dd is running, press Ctrl-T in the >>>> terminal window.
Theo
I tried Alan B's suggestion and it ran OK. But…
A bit of explanation.
The disk was originally a 1TB drive, divided into two equal separate
containers. OK, not a good idea in retrospect. But what's done, is done. >>> One of these was used to hold a bootable system, generated by the system >>> recovery mechanism, and on which the Data drive was kept up to date by Carbon
Copy Cloner at regular intervals. The System drive was updated by booting from
it and using Software Update. All perfectly standard.
The other was partitioned into two by the approved Disk Utility method and >>> each held a CCC copy of my data disk, updated on alternate weeks.
Alan's technique produced a single volume - but it was only 500GB. It looks as
though one of the two containers has been obliterated. So I thought that I >>> would try Theo's method, to see if it would recover the whole space.
But when I tried it, I got the response "dd: /dev/rdisk2: Resource busy". >>
retry Theo's command.
It might be useful to see the output of the 'diskutil list' command with the >> drive inserted and hence mounted before you try again.
I get
Last login: Fri Jun 14 07:33:24 on ttys000
johnhill@Johns-iMac ~ % diskutil list
/dev/disk0 (internal, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *500.3 GB disk0
1: EFI EFI 314.6 MB disk0s1
2: Apple_APFS Container disk1 500.0 GB disk0s2
/dev/disk1 (synthesized):
#: TYPE NAME SIZE IDENTIFIER
0: APFS Container Scheme - +500.0 GB disk1
Physical Store disk0s2
1: APFS Volume Big Sur - Data 451.7 GB disk1s1
2: APFS Volume Preboot 2.1 GB disk1s2
3: APFS Volume Recovery 1.2 GB disk1s3
4: APFS Volume VM 3.2 GB disk1s4
5: APFS Volume John's HD 9.3 GB disk1s5
6: APFS Snapshot com.apple.os.update-... 9.3 GB disk1s5s1
/dev/disk2 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *500.1 GB disk2
1: EFI EFI 209.7 MB disk2s1
2: Apple_APFS Container disk3 499.9 GB disk2s2
/dev/disk3 (synthesized):
#: TYPE NAME SIZE IDENTIFIER
0: APFS Container Scheme - +499.9 GB disk3
Physical Store disk2s2
1: APFS Volume Untitled 1.2 MB disk3s1
johnhill@Johns-iMac ~ %
So it clearly is disk2
On 2024-06-13, John Hill <watcombeman@yahoo.co.uk> wrote:
On 12 Jun 2024 at 14:04:41 BST, "Theo" <theom+news@chiark.greenend.org.uk> >> wrote:
Alan B <alanrichardbarker@gmail.com.invalid> wrote:
On 2024-06-12, John Hill <watcombeman@yahoo.co.uk> wrote:
I seem to have wrecked an external Sandisk SSD drive experimenting with File
Vault, at least so far as my iMac is concerned. It seems to sort of mount but
cannot be ejected. Nor can Disk Utility do anything with it - it just locks
up. And I cannot eject it.
It is formatted APFS, so AIUI Disk Warrior cannot handle it.
Is there any app that might possibly rescue it, or is it likely to be >>>>> effectively a brick? Obviously any rescue would have to cost less than the
value of the drive!
I have no need to rescue any of the content, just to erase and reformat the
drive.
I've occasionally had problems with DU being unable to erase drives. I've found
that using the command line sometimes, but only sometimes, works.
Assuming the drive mounts OK, use 'diskutil list' to get its drive number. Then
use 'sudo diskutil eraseDisk APFS Untitled diskn' to erase it, where
'Untitled' is the
volume name which you can set as you wish of course. Replace 'n' with the >>>> number
shown in the 'diskutil list' command. Be very, very careful to get the value
of 'n'
correct or you could have a disaster!
A cruder approach is just to nuke everything on it, not even using diskutil.
Run 'diskutil list' to get the drive number as above. eg 'disk2'.
It will definitely not be disk0 (that's your internal SSD) and perhaps not >>> disk1.
Then run:
sudo dd if=/dev/zero of=/dev/rdisk2 bs=104857600
It'll take a long time (maybe hours) but you'll have a completely zeroed out
device, no volumes, no APFS, no partitions, nothing. You can then try to >>> set it up from scratch again.
If you want a progress report while dd is running, press Ctrl-T in the
terminal window.
Theo
I tried Alan B's suggestion and it ran OK. But…
A bit of explanation.
The disk was originally a 1TB drive, divided into two equal separate
containers. OK, not a good idea in retrospect. But what's done, is done.
One of these was used to hold a bootable system, generated by the system
recovery mechanism, and on which the Data drive was kept up to date by Carbon
Copy Cloner at regular intervals. The System drive was updated by booting from
it and using Software Update. All perfectly standard.
The other was partitioned into two by the approved Disk Utility method and >> each held a CCC copy of my data disk, updated on alternate weeks.
Alan's technique produced a single volume - but it was only 500GB. It looks as
though one of the two containers has been obliterated. So I thought that I >> would try Theo's method, to see if it would recover the whole space.
But when I tried it, I got the response "dd: /dev/rdisk2: Resource busy".
It needs to be unmounted -> 'diskutil unmountDisk disk2' ought to do that, then
retry Theo's command.
It might be useful to see the output of the 'diskutil list' command with the drive inserted and hence mounted before you try again.
So I reckon the following terminal 2 commands should zap the SSD:
1) diskutil unmountDisk disk2
Followed by Theo’s suggestion:
2) sudo dd if=/dev/zero of=/dev/rdisk2 bs=104857600
You should then be able to reformat the SSD using the Disk Utility application.
I tried this out with a 64GB USB3 memory stick and it seemed to work OK.
Sure it takes a long time but maybe you can cancel the dd command after a short while unless you want to completely zeroise the SSD?
Alan B <alanrichardbarker@gmail.com.invalid> wrote:
So I reckon the following terminal 2 commands should zap the SSD:
1) diskutil unmountDisk disk2
Followed by Theo’s suggestion:
2) sudo dd if=/dev/zero of=/dev/rdisk2 bs=104857600
You should then be able to reformat the SSD using the Disk Utility
application.
I tried this out with a 64GB USB3 memory stick and it seemed to work OK.
Sure it takes a long time but maybe you can cancel the dd command after a
short while unless you want to completely zeroise the SSD?
GPT stores a backup partition table at the end of the disc ...
... so a full wipe
nukes this too, otherwise it may still be hanging around and tools could decide to 'fix' things by restoring it. However just wiping the
beginning may be enough to prevent APFS/Disk Utility from trying to use the disc and so causing the reported problems.
It would be fair to let dd run for a little while, then stop it, unplug and replug the drive and see if it fixed the problem. If the problem remains, then try a full wipe by letting dd run to completion (eg overnight).
Alan B <alanrichardbarker@gmail.com.invalid> wrote:
So I reckon the following terminal 2 commands should zap the SSD:
1) diskutil unmountDisk disk2
Followed by Theo’s suggestion:
2) sudo dd if=/dev/zero of=/dev/rdisk2 bs=104857600
You should then be able to reformat the SSD using the Disk Utility
application.
I tried this out with a 64GB USB3 memory stick and it seemed to work OK.
Sure it takes a long time but maybe you can cancel the dd command after a
short while unless you want to completely zeroise the SSD?
GPT stores a backup partition table at the end of the disc, so a full wipe nukes this too, otherwise it may still be hanging around and tools could decide to 'fix' things by restoring it. However just wiping the
beginning may be enough to prevent APFS/Disk Utility from trying to use the disc and so causing the reported problems.
It would be fair to let dd run for a little while, then stop it, unplug and replug the drive and see if it fixed the problem. If the problem remains, then try a full wipe by letting dd run to completion (eg overnight).
Theo
The run completed OK and faster than I anticipated. USB3 makes such a difference. I have formatted the drive and it is now at nominal capacity. There is still a question in my mind - whether to continue using it as an off-site backup drive as before, or use a Crucial drive as possibly being more
reliable. My eldest son reinforces the opinion that ScanDisk drives are not the last word in reliability, and a backup drive must be trustworthy.
Thank you all for helping me with this problem. I shall keep the instructionsjust in case.
On 14 Jun 2024 at 12:10:26 BST, "Theo" <theom+news@chiark.greenend.org.uk> wrote:
Alan B <alanrichardbarker@gmail.com.invalid> wrote:
So I reckon the following terminal 2 commands should zap the SSD:
1) diskutil unmountDisk disk2
Followed by Theo’s suggestion:
2) sudo dd if=/dev/zero of=/dev/rdisk2 bs=104857600
You should then be able to reformat the SSD using the Disk Utility
application.
I tried this out with a 64GB USB3 memory stick and it seemed to work OK. >>> Sure it takes a long time but maybe you can cancel the dd command after a >>> short while unless you want to completely zeroise the SSD?
GPT stores a backup partition table at the end of the disc, so a full wipe >> nukes this too, otherwise it may still be hanging around and tools could
decide to 'fix' things by restoring it. However just wiping the
beginning may be enough to prevent APFS/Disk Utility from trying to use the >> disc and so causing the reported problems.
It would be fair to let dd run for a little while, then stop it, unplug and >> replug the drive and see if it fixed the problem. If the problem remains, >> then try a full wipe by letting dd run to completion (eg overnight).
Theo
The run completed OK and faster than I anticipated. USB3 makes such a difference. I have formatted the drive and it is now at nominal capacity. There is still a question in my mind - whether to continue using it as an off-site backup drive as before, or use a Crucial drive as possibly being more
reliable. My eldest son reinforces the opinion that ScanDisk drives are not the last word in reliability, and a backup drive must be trustworthy.
Thank you all for helping me with this problem. I shall keep the instructionsjust in case.
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