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I burned an ISO a long time back in a Pen Drive. How to check whether the burned one in the Pen Drive is MBR or GPT ? Is it possible to tell the partition scheme by the folder structure ?
What happens when we changing the partition scheme in Rufus ?
SmartManoj
Posted 2019-07-27T15:16:29.287
Reputation: 208
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Use gdisk to know if usb is mbr or gpt first.. on windows if you have one hard disk and external usb connected you can use the command "gdisk 1:" from cmd ( don't forget to run cmd as administrator) if the result was that you have gpt with protective mbr your usb stick is using GPT , overwise your usb is using MBR .. you can enter p to check that it's your usb because usb stick partition table information will be shown. If you have GPT and want to check if you are booting from USB under UEFI Mode or legacy mode ( because gpt disks can also be booted from under legacy mode ) you can check usb file system if it's FAT32 and have EFI folder inside it then you are probably boot from it under UEFI but to be sure try entering your BIOS Setup and disable Legacy mode (CSM Mode) by choose only UEFI then boot your device from usb. It will boot using only EFI bootloader. Your computer must be UEFI compatible first to be able to boot using this way.
Mohamed Faky
Posted 2019-07-27T15:16:29.287
Reputation: 36
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Rufus offers you some options with partition table.. If you used MBR then your usb will be formatted using master boot record and iso file will be burned on it.. this will make first 512 byte have operating system's bootloader and partition table which is your usb partition that has other files.. with this way BIOS will read and boot using the first 512 byte on your usb and this is the old way that all computers was boot using. If you choose GPT then if operating system installer inside iso is support EFI booting ( with the new booting way ) Rufus will write GUID Partition table and make the first 512 byte is Protective mbr that doesn't have bootloader on it, with this booting way the bootloader is placed on the partition as bootx64.efi or something else, this way requires that your computer support it, you must have an UEFI Computer to boot using this way. You can also choose gpt with legacy mode (which is the old boot way on newest partition table) this way will make a gpt disk and use protective mbr to write the bootloader inside it and some BIOSes can boot using this way. (this way is somehow useless..)
Mohamed Faky
Posted 2019-07-27T15:16:29.287
Reputation: 36
bootx64.efi or something else - expected this only ! For MBR which name ?? – SmartManoj – 2019-07-28T00:28:01.927
1For mbr, bootloader is just a code on first 512 byte, for sure there is second stage bootloader that it's name bootmgr ( on windows USB MBR installer ) and bootmgr.efi ( on windows USB GPT installer ) – Mohamed Faky – 2019-07-28T00:38:20.677
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How to check whether the bootable one is MBR or GPT?
Launch C:\WINDOWS\System32\msinfo32.exe there will be an entry for BIOS Mode it will either say Legacy or UEFI. If you are using MBR it will indicate Legacy, if you are using GPT, it will indicate UEFI.
You can also view the properties of the drive within Computer Management which will indicate the partition style.
Is it possible to tell the partition scheme by the folder structure?
The folder structure of an MBR and GPT partition is identical.
Ramhound
Posted 2019-07-27T15:16:29.287
Reputation: 28 517
in the Pen Drive ? – SmartManoj – 2019-07-27T23:51:54.613
Yes; indeed that will work – Ramhound – 2019-07-28T01:51:34.717
that refers to ? – SmartManoj – 2019-07-28T01:54:43.083
@SmartManoj - What are you referring to exactly? You can view the properties of a removable mass storage device in Computer Management. I won’t be answering anymore additional questions you might have in the comment section – Ramhound – 2019-07-28T02:17:21.453
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The terms MBR or GPT have no relation to an ISO.
A ISO file is an image file of a block device containing an ISO 9660 filesystem. It contains an exact representation, sector-by-sector, of the data as it would have been stored on a CD of indeterminate size.
An ISO can be bootable, just as a CD is bootable, but it is not a disk. The concepts of MBR or GPT have no meaning for it.
If the ISO contains an installation, this installation can be done to a disk that is either MBR or GPT. The installation program might insist on one of these disk formats, but these concepts do not apply to the ISO itself.
harrymc
Posted 2019-07-27T15:16:29.287
Reputation: 306 093
in the Pen Drive ? – SmartManoj – 2019-07-27T23:53:21.550
Technically you are right, but the term ISO Files is also often used for disk images with different filesystem, and the typical flash „burner“ programs don’t care much about the actual filesystem and/or block layout. – eckes – 2019-07-28T19:00:20.210
For windows Diskpart -> List disk will show – SmartManoj – 2019-07-28T00:14:13.807
1Yes this is also a way using windows diskpart when typing list disk then if you have GPT Disk you’ll see an asterisk character () under the “Gpt” column. If you don’t see (), then usb is using MBR.. you can also access this info using Disk management tool in windows, i 'm using gdisk on windows many times so this was the best way for me. – Mohamed Faky – 2019-07-28T00:45:02.153