Unintialized Drive "Unable to write to the last block of the device." + Size Error ?

[DMP21]

I have a Late 2013 iMac.
The original fusion drive size is 3Tb but for some reason it shows only 4,14Gb (ref 1st screenshot from Disk Utility)

I do have a suspicion why.... I had the misfortunate some year back of using MacKeeper ( and yes I know that was a disaster) I finally found out when I called Apple Support and was promptly to install a Malware checker and finally deleted them.

I don't heavily use my iMac I tend to use my Macbook Pro due to travelling but I need to use it now and install a lot of app but found upon checking that the 3Tb drive has "shrunk" or well vanished... I don't know how else to change it.

I have tried to Erase and format it as APFS with scheme GUID Partition Map since I have an Intel CPU (ref 2nd screenshot) but this fails due to an error "
Unable to write to the last block of the device." (ref 3rd screenshot)
I have tried all other combinations with the same outcome... I am stumped.

Does anyone have any ideas how else I can just initialize the drive to start with or is this dead?
Or do I need to swap it out for another, I have several 1Tb drives that would do in a pinch?
Also can anyone explain how to understand / check how a drive size can change or is this likely the sign the drive is dead?

Many thanks in advance for any useful suggestions.
Any help appreciated.

 

[MacInWin]

Welcome to the forum.Try selecting the hardware line (the one that shows as "APPLE SSD..." in Disk Utility, then Erase and see if you get all the space back. A fusion drive has a spinner drive component and a small SSD component fused together logically in an attempt to get some additional speed over the rotating disk drives.

The two may have become unfused, but Disc Utility isn't showing it that way, so we can hope that the erasing at the hardware level will work.

 

[DMP21]

Hi, (Happy New Year)

Thanks for the reply and suggestion MacInWin
I thought obviously the best precaution in case something went wrong is to make a full backup.
The easiest way I thought to do this was use Disk Utility and create and image and then the next problem start, anything thoughts?

I selected my APPLE SSD... drive and just kept the default names/settings and well basically the operation was cancelled... (I should ask here, if I should create a separate thread and link back to this topic since I'm going off topic somewhat), for now I'll continue and break it out later if need be, so thx.

I've added the screenshots, note I was clear to make sure not to include the ST3000.... drive in the Disk Image selection...

So again I'm stumped so will do some searching on our forum but if anyone's got some insight I'm happy to learn more...

Thank in advance again.

---

David

 

[ferrarr]

In my opinion, the easiest way to make a backup of all of your data is Time machine. If you prefer a "clone" then you can use either Carbon Copy Cloner, or SuperDuper!. They are free to try and with limited options after the trial period is over.

 

[MacInWin]

I have tried to Erase and format it as APFS with scheme GUID Partition Map since I have an Intel CPU (ref 2nd screenshot) but this fails due to an error "

I am confused. You erased the drive, and now you are trying to back it up? As soon as you clicked "Erase," the data was erased. Nothing there to back up at this point.

Or is there something you haven't told us?

 

[DMP21]

I am confused. You erased the drive, and now you are trying to back it up? As soon as you clicked "Erase," the data was erased. Nothing there to back up at this point.

Or is there something you haven't told us?

Apologies for any (unintended) confusion on my part.

I did say in my very first post that I tried to erase the drive, I have still yet to succeed in doing this. The attempt at erasing my drive ST3000.... failed, see the screenshot from post #1 I have reattached for ref.

I did not mean by saying that I wanted to back up my drive that I had succeed, in fact the problem still exists.

I was in fact thinking about your suggest to try and Erase the APPLE SSD drive and not the ST3000 drive as I had unsuccessfully previously tried. But before I attempted this I wanted to create a back of my entire drive, though I have not done this previously but do have Time Machine, 12Tb working (since 2017) so I'll likely have plenty of backups.

I just wanted to have a single clean snapshot I could recall in one go should Erasing APPLE SSD not fix the unfused spinner component. I would hopefully be able to boot into Recovery mode and just select the full back up and reinstall it back to it previous state.... until I can obtain another drive... (I actually have some spare 1Tb drives I could use, just need to clear them off.)

But changing a drive is a bit more of a challenge, not tremendously, just needs some time and preparation, need to order some double sided tape to reattach the screen.

So if I have understood correctly that if this does not work I would likely have to replace the physically drive.. does that sound right?

Hope this clears this up a bit and again, sorry for the misunderstanding as I might not have made myself as clear as I could have.

Thanks again for the time and support, it's appreciated.

Hope the New Year is a great one

 

[vansmith]

Word on the internet is that this is frequently caused by a bad cable connection. However, if this is your internal drive, this is less likely the case.

Secure Erase might be helpful here in really giving the drive a clean scrub, wiping any troublesome blocks (and everything for that matter). That will take a very long time so might want to do it when you don't need that drive for an extended period of time (overnight maybe?).

 

[DMP21]

Word on the internet is that this is frequently caused by a bad cable connection. However, if this is your internal drive, this is less likely the case.

Secure Erase might be helpful here in really giving the drive a clean scrub, wiping any troublesome blocks (and everything for that matter). That will take a very long time so might want to do it when you don't need that drive for an extended period of time (overnight maybe?).

Hi vansmith,

Thanks for the feedback, I would like to give Secure Erase a try and see that will fix it.
However before I do that I would like to make an Image snapshot of the drive just in case, per the 1st screenshot.
Problem is that this fails, see 2nd screenshot..??.. I have no idea what is going on with this system, the operation is just, well, cancelled.
The strange thing is that there is no error msg that I could search for related issues or report on.
I will do some searching in the forums and Google but I'd like to get an up to date Image before I go and wipe the system...
Call me paranoid but I'm sure if I don't somethings going to go awry ....

Thanks again for taking the time to reply with your ideas.

 

[MacInWin]

What is in Container 3? You've never posted an image with it expanded. Maybe that will give us some clue to what is going on. I still think that somehow the fusion drive was un-fused, and what you are seeing are the separate devices of the smaller SSD and larger rotating drive. If that is, in fact, what happened then nothing on either of them will be recoverable.

 

[DMP21]

What is in Container 3? You've never posted an image with it expanded.

Hi MacInWin,

Thanks for the reply, actually, if you check back to Post #1 you will see I did post this image expanded.

But I don't doubt what you say the Fusion drive has become unfused since I can see it but not access it, nor can I erase it without getting the error.

Could you clarify what you mean by your statement

I still think that somehow the fusion drive was un-fused, and what you are seeing are the separate devices of the smaller SSD and larger rotating drive. If that is, in fact, what happened then nothing on either of them will be recoverable.

How do you mean 'nothing on either of them will be recoverable' can you clarify this further?
Recover in what way do you mean that I will not be able to recover, I assume all the data?
Or do you mean that if I erase all the drives to try and see if the Fusion drive, that being the SSD and the 3T (Rotating) HDD, to reconnect or rather re-fuse this will fail?
The system all ready is performing all regular backups to the Time Machine so sorry but I'm not sure I follow in what way you mean nothing will be recoverable.
Also then do you mean that if the drives (SSD and rotating HDD) do not refuse that I cannot just perform a restore from Time Machine backup?

 

[MacInWin]

OK, I missed that image.

A bit of background for you. A fusion drive is a hybrid of a small solid state drive and a rotating drive. The idea is that the reads/writes go to the SSD as much as possible to give performance, then the "idled" files on the SSD are moved to the rotational drive as time permits. Reads and writes to the rotating drive are avoided as much as possible. So, when you open a file, it gets moved from the rotating drive to the SSD so you get great performance. Then when you are done with it, it gets written to the SSD to be quick, and later on the fusion software will move it back to the rotating drive when the drive is otherwise idle. Basically, to make it look like one drive to the system, the two are "fused" with software into one logical drive. It's a good way to get performance out of slower rotating drives without the full cost of a large SSD, but it has the decided vulnerability in that if EITHER of the two drives have problems, or if they become de-fused, the shared information on what is stored where is lost, data integrity is lost and the entire fused drive becomes un-recoverable. Nothing can read what was there because there isn't any clear record of what was there or where things were stored. And given that it's constantly in flux, there could even be files caught in mid-move at the time of the problem.

So, that is what I mean. If it was a fused drive and is now unfused, there isn't anything to read, or write or make a backup or do just about anything with that setup. Re-fusing them won't work because that process will initialize the drives, effectively erasing them.

The system all ready is performing all regular backups to the Time Machine so sorry but I'm not sure I follow in what way you mean nothing will be recoverable.

I don't know what you mean by that statement. TM can't read the unfused drives either. If you have a TM back of the drive before it became unfused, you could re-fuse and restore from that backup, but no backup after the un-fusing will have the data from the fused drive.

it is possible that one of the data recovery services ($$$$) might be able to recover some of the stuff on whichever of the two you haven't erased/formatted, but it's hard to tell if even that is possible.

Bottom line: If it is a de-fused drive that I think it is, the data is gone. If you have a backup, you can recover from there, but without that, in the words of Dr. McCoy of StarTrek, "She's dead, Jim."

 

[DMP21]

OK, I missed that image.


I don't know what you mean by that statement. TM can't read the unfused drives either. If you have a TM back of the drive before it became unfused, you could re-fuse and restore from that backup, but no backup after the un-fusing will have the data from the fused drive.

Bottom line: If it is a de-fused drive that I think it is, the data is gone. If you have a backup, you can recover from there, but without that, in the words of Dr. McCoy of StarTrek, "She's dead, Jim."

Hi MacInWin,

Thanks for taking the time to write a detailed reply.

With respect to these statement I think our experiences differ, my actual experience with my iMac is different.

In your experience what have you found that shows that once the drives are un-fused it will not perform any backup? As mine still performs backups (of the SSD) ref screenshot SSD Backup to Timemachine - current as of 02 Jan 2022.jpg
I can see that the physical backup has not worked for a long time (about the time MacKeeper were "tinkering" with my system.. to "FIX" something hmm?) ref screenshot Mac HDD Backup to Timemachine - stopped 2019.jpg

You say that there is no backup after the un-fusing, for me this is not the case, backups are still made daily for the SSD since that is what I work on. Of course the un-fused drive (the physical rotating HDD) is no longer connected so it is not backed up.

When I check the backups on (CMD + R) looking in the macOS Utilites > Restore From Time Machine Backup - I see all the regular backups. Plus they work as I recently went back and performed a restore of my entire Photo library due to a glitch I made.

But otherwise I see no problems with the SSD backups, so at least I am luck at least I am lucky as in the case of my un-fused drives, it sees them as separate drives and backs them up separately. So my data is not gone, all though I can see the exact time stamp when it stopped. Some years ago since this is not my primary computer.

So hooray she's not (all) dead Jim ;-)

Thanks again for your input.

 

[IWT]

@DMP21 (David),

Jake is the expert here; but I think there little - say no - real doubt that you have a Fusion Drive setup. Your very helpful screenshots show a SSD and another Hard Disk Drive.

I had, some years ago, the exact same setup. It was a bit of a nightmare to be honest. You are correct, TM does back up each separately - I recall this vividly when I bought a new iMac and transferred the data to it - there were two TM backups and they had to be integrated into my Single-Drive new iMac.

Although it worked, to this day, I still have some files in "the wrong place" simply because data was backed up to two TM backups, as you have.

Your big problem, if I may be so bold, is that only your SSD is currently being backed up and there has been no TM backup of your Hard Disk Drive since 2019.

If/when you get a new Mac and want to transfer ALL your data to the SINGLE Drive - (almost certainly a SSD because all recent Macs have an SSD) - I foresee big problems.

The data on the now "dead", or at least unusable, HDD may not be recoverable; partly because it's "full"; partly because the TM backup is so old; partly because the SSD and the HDD are no longer "on speaking terms" as it were.

That's my take on the situation. Let's see if cleverer minds than mine cane come up with a solution.

Ian

 

[MacInWin]

So hooray she's not (all) dead Jim ;-)

OK, well, good luck with it. I hope it all works out.

 

[chscag]

If memory serves me correctly..... Fusion drives of 3TB actually have a 128GB SSD that is fused to it. Smaller Fusion drives wind up with smaller SSDs.

So it would appear the OP has sufficient space on the SSD that has become separated (unfused) from the main spinner drive. Not a good situation but at least workable for him.

 

[MacInWin]

Not so sure it's workable, Charlie. If you look at his backups, the last backup of the spinner was in March, 2019, whereas the recent backups on the smaller SSD are this year. Trying to find two backups to match to try to restore the fused drive will be very difficult, if possible at all. We don't know when or how the fusion drive got un-fused, or what happened to it while unfused except that the OP tried to format the SSD (Post #1). That try failed, but who knows what was done to the drive in that process? Now, it is possible that some of his files on that spinner can be recovered from the backups from 2019, but there is no way of knowing for sure. Maybe at this point the thing to try is to replace the Fusion drive with one of the 1tb drives mentioned in post #1, install a working macOS on it and then see if TM can open the backups of the big drive from 2019.

 

[DMP21]

Hi All,

A word of thanks for your replies and thoughts.

@IWT
Thanks for taking the time to give suggestions and feedback also.

@chscag
What you say is right, it is the Fusion Drive is a 3Tb + 121Gb SSD and (for now) there is enough space for the OP and me to work... but not indefinitely, it's nearly at it's limit.

@MacInWin
You are also right in what you say, it is becoming unworkable, understandable with so little space. I actually need to install Parallels and Windows since I have apps that do not have a macos equivalent.

Also your point about the last backup being 2019 is old, I would like to check them but in the worst case I would consider them lost, after all I cannot remember what might even be there.

I think idea I proposed / what you suggested also about using a spare 1Tb drive and swapping out the 3Tb drive and trying to re-fuse this and see if it works.

---

I have an external drive dock and plug in the 3Tb drive and check if I can at least access it or find out if it is truly dead (fingers crossed becoming un-fused has caused no significant damage).

It was rather coincidental that the time it became 'ahem' non-functional was the last time I let MacKeeper access the system (before I was strongly recommended by an Apple Tech Support to install Malware app and see what it reports, sure enough, I then deleted MacKeeper), sadly I found too late before this all happened.

I had terrible performance issue to the point it would virtually not work so I had MacKeeper perform a downgrade back to High Sierra from Mojave, just thought it was rather coincidental that was the last time they accessed my iMac and the last time I could access the 3Tb drive.

Sadly I've run out of time to work on this furthe for now. I have to return to work early, so I won't have physical access to the iMac to work on it as much as I want to resolve this.

Next time I'll have a chance will be mid-Feb 2022...

So thanks and I hope next time I can give an update to report I have found some answers.

Thanks again for all your help and wish you all a happy, safe and prosperous 2022

Regards

David