NEW iMac problems

[Tom Elliott]

I imagine, however, resizable or not, this is a problem as the way the disk is presented on one system (512 byte sector sizes) to another system (4096 byte sector sizes).

I know there’s a way to adjust a disks byte sector size. Something like:

blockdev --setbsz 512 /dev/nvme0n1

[Tom Elliott]

Maybe we can use information from this posting to help us out? It’s coming from Rod Smith directly and he would probably be the guy who knows his stuff considering he wrote gpt disk utilities.

[Sebastian Roth]

Ahh, now I see. Give me a bit of time with this and I am sure I’ll comes up with a solution to this. Though it might sound like a good idea to set the NVME drive to 512 I don’t think this is wise to do. I have a bit of free time tomorrow and will dive into this more deeply…

[Tom Elliott]

@sebastian-roth I totally understand. I tried in the past and failed miserably, so I don’t mean to put more on your shoulders, I just don’t know how to best approach. In particular, fixing this issue for resize should be simple, but how can we fix for non-resizable images?

[Abuelika]

In the first instance

Many thanks to @sebastian-roth and @Tom-Elliott for the work you are doing.

The fastest solution I have found is the following:

My Solution:

• Mac with SATA ( Sector size: 512 bytes ) hard disk cloned with “FOG”, we created a “TimeMachine” and restored in iMAC computer with M2 disks ( Sector size: 4096 bytes ) .

• We create an image with FOG Multiple Partition Image - Single Disk (Not Resizable)

• Perform a capture of the equipment with disk M2 with “FOG”

• We deploy the image to all iMac computers with M2 hard disks

Work fine!

[george1421]

@tom-elliott While I’m not sure what I can add to this thread, I do have to say I have several 4K sata drives that were purchased before I realized that ESXi didn’t support 4K drives (yet). If you need me to test anything (under linux or ms windows) I have the facilities to do so.

[Sebastian Roth]

@Abuelika Good to hear that you could make this work but I think this is a general issue that we’ll be seeing more and we need to figure this out. I’ve dug my head in the sector count swamp and would like to ask you to test something that I came up with.
Hope you still have that 512 based image somewhere. Please edit the d1.partitions file again and make it look like this:

label: gpt
label-id: EB5F756F-5E64-4990-8B9C-5F2826AFDEC2
device: /dev/nvme0n1
unit: sectors
first-lba: 5
last-lba: 61279312

/dev/nvme0n1p1 : start=           5, size=       51200, type=C12A7328-F81F-11D2-BA4B-00A0C93EC93B, uuid=F803B6B4-FAF1-4700-814F-4CC7B6AA693D, name="EFI System Partition"
/dev/nvme0n1p2 : start=       51205, size=    29095304, type=48465300-0000-11AA-AA11-00306543ECAC, uuid=2CA043B5-1BA4-4052-AC59-AA30F67E556D
/dev/nvme0n1p3 : start=    29146509, size=      158692, type=426F6F74-0000-11AA-AA11-00306543ECAC, uuid=989E4FD8-2721-4B58-A6B4-24E3334F1165, attrs="GUID:49"

Make sure to get the values for *-lba, start and size right. I didn’t change the type or uuid values at all. Then do a deploy to the 4096 machine again.

[Abuelika]

Hi @sebastian-roth

okay. now I’m not in the office, tomorrow at 8:00 am I will do the test. I still have the image.

I leave you the content of d1.partition of the new image made to imac with m2, in case you are interested.

label: dos
label-id: 0x00000000
device: /dev/nvme0n1
unit: sectors

/dev/nvme0n1p1 : start=           2, size=    61279342, type=af

root@fogserver:/images/MASTERMACOS2017_modelnou# ls -l
total 28790796
-rwxrwxrwx 1 root root        1024 sep 13 11:01 d1.mbr
-rwxrwxrwx 1 root root 29481762309 sep 13 11:17 d1p1.img
-rwxrwxrwx 1 root root         132 sep 13 11:01 d1.partitions

[Sebastian Roth]

@abuelika said in NEW iMac problems:

label: dos

What?!??!?! This doesn’t make any sense to me. Mac OS X is UEFI as far as I know, why would they use a legacy DOS/MBR partition layout? You said you transfered the system using TimeMachine? And it does boot properly? That’s crazy I reckon.

[Abuelika]

Hi @sebastian-roth ,

I have modified the file d1.particiones with the facilitated content.

I have now unpacked another iMac with m2 and I’m capturing the image to review the d1.partitions and check the label to see if dos or gpt.

This is the content I have modified from d1.partitions.

label: gpt
label-id: EB5F756F-5E64-4990-8B9C-5F2826AFDEC2
device: /dev/nvme0n1
unit: sectors
first-lba: 5
last-lba: 61279312

/dev/nvme0n1p1 : start=           5, size=       51200, type=C12A7328-F81F-11D2-BA4B-00A0C93EC93B, uuid=F803B6B4-FAF1-4700-814F-4CC7B6AA693D, name="EFI System Partition"
/dev/nvme0n1p2 : start=       51205, size=    29095304, type=48465300-0000-11AA-AA11-00306543ECAC, uuid=2CA043B5-1BA4-4052-AC59-AA30F67E556D
/dev/nvme0n1p3 : start=    29146509, size=      158692, type=426F6F74-0000-11AA-AA11-00306543ECAC, uuid=989E4FD8-2721-4B58-A6B4-24E3334F1165, attrs="GUID:49"

Result:

[Abuelika]

Hi @sebastian-roth

I’ve unpacked an imac with M2 and I captured the image.
The contents of the d1.partitions file:

label: gpt
label-id: 7D761C2A-8679-400C-9795-BFCB65054221
device: /dev/nvme0n1
unit: sectors
first-lba: 6
last-lba: 61279338

/dev/nvme0n1p1 : start=           6, size=       76800, type=C12A7328-F81F-11D2-BA4B-00A0C93EC93B, uuid=E40E5108-F939-489B-BC7B-0E77CE5E42E3, name="EFI System Partition"
/dev/nvme0n1p2 : start=       76806, size=    61043841, type=53746F72-6167-11AA-AA11-00306543ECAC, uuid=81584085-44EC-4186-A82C-FC857C07A63E
/dev/nvme0n1p3 : start=    61120647, size=      158692, type=426F6F74-0000-11AA-AA11-00306543ECAC, uuid=0C9A6601-5C3C-4A73-8E52-A74AFAE873CC, name="Booter", attrs="GUID:49"

the contents of the folder

root@fogserver:/images/MACNOU-NET# ls -l
total 18645544
-rwxrwxrwx 1 root root       17920 sep 14 09:06 d1.mbr
-rwxrwxrwx 1 root root         249 sep 14 09:06 d1.original.uuids
-rwxrwxrwx 1 root root    14480899 sep 14 09:06 d1p1.img
-rwxrwxrwx 1 root root 18527785416 sep 14 09:58 d1p2.img
-rwxrwxrwx 1 root root   550725927 sep 14 09:59 d1p3.img
-rwxrwxrwx 1 root root         610 sep 14 09:06 d1.partitions

I think the problem of label: dos is that an empty disc was recovered with “TimeMachine” without an operating system.

Now I am doing a capture of an iMac with M2 with operating system and restored with TimeMachine.

[Sebastian Roth]

@Abuelika Thanks for trying and posting results. It’s good to know how the partition table on a fresh machine looks like and from the numbers it seems like I am not too far of it. Though we can’t directly compare the numbers I think as those were created by a someone else. But definitely good to know that my calculated numbers are kind of in that same range.

Please add isdebug=yes ismajordebug=1 again, try my suggested partition table again (first-lba: 5) and post a picture of the output on screen. So we see if it is the very same or a different error.

I compared the tables and the main difference from my point of view is that the new one you posted is starting at sector 6 whereas I calculated it to start at sector 5 (original 40 divided by eight (4096/512)). In an UEFI style system we should be able to move partitions as the boot loader doesn’t rely on sector counts. So you might also try this one (all partitions shifted by one sector):

label: gpt
label-id: EB5F756F-5E64-4990-8B9C-5F2826AFDEC2
device: /dev/nvme0n1
unit: sectors
first-lba: 6
last-lba: 61279312

/dev/nvme0n1p1 : start=           6, size=       51200, type=C12A7328-F81F-11D2-BA4B-00A0C93EC93B, uuid=F803B6B4-FAF1-4700-814F-4CC7B6AA693D, name="EFI System Partition"
/dev/nvme0n1p2 : start=       51206, size=    29095304, type=48465300-0000-11AA-AA11-00306543ECAC, uuid=2CA043B5-1BA4-4052-AC59-AA30F67E556D
/dev/nvme0n1p3 : start=    29146510, size=      158692, type=426F6F74-0000-11AA-AA11-00306543ECAC, uuid=989E4FD8-2721-4B58-A6B4-24E3334F1165, attrs="GUID:49"

[Abuelika]

Hi @sebastian-roth ,

Results with the following d1.partitions

label: gpt
label-id: EB5F756F-5E64-4990-8B9C-5F2826AFDEC2
device: /dev/nvme0n1
unit: sectors
first-lba: 5
last-lba: 61279312

/dev/nvme0n1p1 : start=           5, size=       51200, type=C12A7328-F81F-11D2-BA4B-00A0C93EC93B, uuid=F803B6B4-FAF1-4700-814F-4CC7B6AA693D, name="EFI System Partition"
/dev/nvme0n1p2 : start=       51205, size=    29095304, type=48465300-0000-11AA-AA11-00306543ECAC, uuid=2CA043B5-1BA4-4052-AC59-AA30F67E556D
/dev/nvme0n1p3 : start=    29146509, size=      158692, type=426F6F74-0000-11AA-AA11-00306543ECAC, uuid=989E4FD8-2721-4B58-A6B4-24E3334F1165, attrs="GUID:49"

Results with the following d1.partitions

label: gpt
label-id: EB5F756F-5E64-4990-8B9C-5F2826AFDEC2
device: /dev/nvme0n1
unit: sectors
first-lba: 6
last-lba: 61279312

/dev/nvme0n1p1 : start=           6, size=       51200, type=C12A7328-F81F-11D2-BA4B-00A0C93EC93B, uuid=F803B6B4-FAF1-4700-814F-4CC7B6AA693D, name="EFI System Partition"
/dev/nvme0n1p2 : start=       51206, size=    29095304, type=48465300-0000-11AA-AA11-00306543ECAC, uuid=2CA043B5-1BA4-4052-AC59-AA30F67E556D
/dev/nvme0n1p3 : start=    29146510, size=      158692, type=426F6F74-0000-11AA-AA11-00306543ECAC, uuid=989E4FD8-2721-4B58-A6B4-24E3334F1165, attrs="GUID:49"

[Sebastian Roth]

@Abuelika I have looked into bringing up a VM with physical sector size of 4096 but still couldn’t make it work. Though I have the qemu/kvm command line options it doesn’t work yet. I hope to get this ready soon.

[Sebastian Roth]

Getting there just give me more time…

[Sebastian Roth]

@Abuelika I think I found what’s wrong. Though I don’t know yet how to fix it. The problem is that we have d1.mbr based on 512 sector size as well as d1.partitions. So my changed d1.partitions didn’t do the trick. I am sure I can come up with something but still need a bit more time.

[Sebastian Roth]

Just bumping this so I don’t loose track of it.

[Sebastian Roth]

And again…