Cloning an install on a smaller Drive

bloodline · Dec 12, 2018

Ok I have a weird problem.

I purchased a 1050Gb SSD a few years ago and managed to get a nice stable Sirra install running on my build.

Over the Black Friday period I purchased a 1000Gb SSD (I didn’t realise it was 50Gb smaller at time of purchase as it was the same brand of drive), with the idea that I would clone my install and then attempt an upgrade... if anything goes wrong just put the original disk back in the machine... nice an easy.... also good to have a back up in general.

So I imaged my 1050 Disk to a my 4TB work drive, and now I have a problem... I can’t image the 1000Gb disk with the 1050Gb image because it it 50gb too big. The main partition on the 1050Gb drive/image is only 300Gb full...

Is there a way to shrink the main partition by 50Gb, and move the “Apple Boot” partition down (as it currently sits above the 1000gb size limit I have (using HDIutil to see the layout of the image).

Many thanks for looking at my problem

UtterDisbelief · Dec 12, 2018

bloodline said:
Ok I have a weird problem.

I purchased a 1050Gb SSD a few years ago and managed to get a nice stable Sirra install running on my build.

Over the Black Friday period I purchased a 1000Gb SSD (I didn’t realise it was 50Gb smaller at time of purchase as it was the same brand of drive), with the idea that I would clone my install and then attempt an upgrade... if anything goes wrong just put the original disk back in the machine... nice an easy.... also good to have a back up in general.

So I imaged my 1050 Disk to a my 4TB work drive, and now I have a problem... I can’t image the 1000Gb disk with the 1050Gb image because it it 50gb too big. The main partition on the 1050Gb drive/image is only 300Gb full...

Is there a way to shrink the main partition by 50Gb, and move the “Apple Boot” partition down (as it currently sits above the 1000gb size limit I have (using HDIutil to see the layout of the image).

Many thanks for looking at my problem

That's an annoying problem, but I know what you mean - I have a 120GB SSD and a 128GB SSD - same problem if I want to do this.

Okay, I wonder if you could use the BootCamp Utility to resize the macOS partition. I can't guarantee it will allow you to get what you need ...

OR

Another piece of software that will definitely do this is by Paragon-Software called Hard Disk Manager for Mac . It will resize a macOS partition - but it costs money. However there is a 10-day free trial available to download.

I'm sure there are other titles available but I have used Paragon and it did the resizing. I'm not sure about the backup imaging software though..

bloodline · Dec 12, 2018

UtterDisbelief said:
That's an annoying problem, but I know what you mean - I have a 120GB SSD and a 128GB SSD - same problem if I want to do this.

Okay, I wonder if you could use the BootCamp Utility to resize the macOS partition. I can't guarantee it will allow you to get what you need ...

OR

Another piece of software that will definitely do this is by Paragon-Software called Hard Disk Manager for Mac . It will resize a macOS partition - but it costs money. However there is a 10-day free trial available to download.

I'm sure there are other titles available but I have used Paragon and it did the resizing. I'm not sure about the backup imaging software though..

Hi there, Many thanks for your input here!

Ok, so Boot Camp appears to split the main partition, so it might make the main partition smaller, it fills the space with room for the Windows partition, leaving the Apple Boot partition at the end of the drive... Where I suspect the EFI expects to find it

Again with the paragon software, it will happily resize, but is careful to leave the partition start positions alone.

My drive layout is thus:

Code:

Matts-MacBook-Air:~ matt$ sudo hdiutil pmap /Volumes/ThreeTerra/WorkStation.dmg

MEDIA: ""; Size 978 GB [2051200368 x 512]; Max Transfer Blocks 2048

SCHEME: 1 GPT, "GPT Partition Scheme" [16]

SECTION: 1 Type:'MAP'; Size 978 GB [2051200368 x 512]; Offset 34 Blocks (2051200301 + 67) x 512

ID Type                 Offset       Size         Name                      (3)

-- -------------------- ------------ ------------ -------------------- --------

 1 EFI                            40       409600 EFI System Partition

 2 Apple_HFS                  409640   2049521152

 3 Apple_Boot             2049930792      1269536

The problem I have is that I need to make partition 2 50GB smaller, and move partition 3 50GB further down (the offsets above are in 512byte blocks).

Now I could, as you say, resize partition 2 so that it is smaller, then use the unix command dd to write the third partition to a lower location... but if I do that I imagine the EFI is not going to be able to find the boot partition... we need an EFI/Filesystem expert to help overcome my lack of understanding.

bloodline · Dec 14, 2018

Ok, so it looks like no-one has attempted to do this before so I'm going to try some things.

Approach 1: Do a fresh install of High Sierra on the smaller disk, then using dd copy over the new EFI and Apple_Boot partitions with the ones from my larger disk... If that disk boots ok, then transfer the data using the migration assistant.

Approach 2: Shrink the HFS partition to 998GB, using dd copy the EFI and Apple_HFS partitions over to the smaller disk. Then copy the Apple_Boot to the new position... Then edit the GPT to reflect the new position... (spent last night reading about the GPT, so should be quite easy to write an editor).

Approach 3: some hybrid of the other 2... And whatever I have time for...

-Edit- Scratch that... resizing the main partition appears to have put the new partition after the Apple_Boot... This might simply need a dd of the first three partitions to the new disk :-D I'm aware the backup GPT won't be copied.. but lets see how far we get.

UtterDisbelief · Dec 14, 2018

bloodline said:
Ok, so it looks like no-one has attempted to do this before so I'm going to try some things.

Approach 1: Do a fresh install of High Sierra on the smaller disk, then using dd copy over the new EFI and Apple_Boot partitions with the ones from my larger disk... If that disk boots ok, then transfer the data using the migration assistant.

Approach 2: Shrink the HFS partition to 998GB, using dd copy the EFI and Apple_HFS partitions over to the smaller disk. Then copy the Apple_Boot to the new position... Then edit the GPT to reflect the new position... (spent last night reading about the GPT, so should be quite easy to write an editor).

Approach 3: some hybrid of the other 2... And whatever I have time for...

-Edit- Scratch that... resizing the main partition appears to have put the new partition after the Apple_Boot... This might simply need a dd of the first three partitions to the new disk :-D I'm aware the backup GPT won't be copied.. but lets see how far we get.

Good luck! It will be interesting to read how you get on :thumbup:

bloodline · Dec 14, 2018

UtterDisbelief said:
Good luck! It will be interesting to read how you get on

Ok... so I mounted the 1050Gb drive image, opened up Disk Utility, and resized the partition so that it was 52GB smaller (I figured 2GB would be a safe margin of error I’d not miss)... then just sudo dd if=image of=/dev/rdisk4 bs=1m (where disk4 is the 1000GB drive... and bingo it boots just fine

bloodline · Dec 14, 2018

The problem I face now is that when I try and upgrade to High-Sierra, the installer does the install, after - few min, black screen with the Apple logo and progress bar etc... reboot back into Sierra...

I’m not sure what’s going wrong!

UtterDisbelief · Dec 14, 2018

bloodline said:
The problem I face now is that when I try and upgrade to High-Sierra, the installer does the install, after - few min, black screen with the Apple logo and progress bar etc... reboot back into Sierra... I’m not sure what’s going wrong!

Well done on the disk resizing :thumbup:

As for the High Sierra installation - I know it's obvious so I apologise if you've covered this already - but when you first install HS it actually just sets up the files and reboots. Clover then gives you three boot options (assuming no UniBeast stick is present, if so the fourth is labelled External etc) - Boot to Install HS, Boot to Sierra (original still there) and Recovery. Choose the left-most option until, after reboots, it disappears and only two are left. You should then boot High Sierra.

bloodline · Dec 15, 2018

It’s been so long since I did a Hackintosh upgrade (El Captain -> Sierra), I have totally forgotten about the bootloader stage!

So I need to renter the bootloader during boot? I think I have to hold down F1 or something...

I’m off to Strasbourg for a few days... so I’ll have to pick this up next week! But thank you for your support and advice so far!

-edit- I had hoped to move to Mojave, but I won’t until NVidia GFX cards are supported

UtterDisbelief · Dec 16, 2018

bloodline said:
It’s been so long since I did a Hackintosh upgrade (El Captain -> Sierra), I have totally forgotten about the bootloader stage!

So I need to renter the bootloader during boot? I think I have to hold down F1 or something...

I’m off to Strasbourg for a few days... so I’ll have to pick this up next week! But thank you for your support and advice so far!

-edit- I had hoped to move to Mojave, but I won’t until NVidia GFX cards are supported

The Clover bootloader will have an extra entry "Boot to High Sierra Installation" or something similar, until the process is complete. Use this Clover option, through the reboots, until it finally disappears leaving you with the High Sierra Boot and Recovery icons only. :thumbup:

(No need to go into the BIOS boot selection at all)

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