Questions tagged [mbr]

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77
votes
7answers
113k views

GPT or MBR: How do I know?

How can I tell whether my harddrive is laid out using an MBR or GPT format?
32
votes
5answers
141k views

Remove GPT - Default back to MBR

I keep receiving this error: Warning!! Unsupported GPT (GUID Partition Table) detected. Use GNU Parted I want to go back to the normal MBR. I found some advice here and did: parted /dev/sda ...
11
votes
4answers
34k views

Moving /boot and MBR to a new drive

I have a CentOS 6 server with two hard drives in it. My old 3TB drive has been giving me some issues so I'm moving things over to a new drive. Because my / and /home partition are managed by a LVM ...
10
votes
2answers
5k views

area on disk after the MBR and before the partition start-point

If I use a MBR partitioning scheme and create a primary or extended partition with fdisk(version 2.20.1), then it starts on sector 2048. If I remember correctly, then older versions of fdisk started ...
8
votes
1answer
7k views

How to boot FreeBSD system with broken bootcode?

I have an HDD (or SSD, or flash drive) with FreeBSD installed on it, and somehow I broke the bootcode (first 446 bytes of MBR). How could I boot into this FreeBSD?
8
votes
3answers
3k views

Linux/GParted can see partition table but dd bs=512 count=1 can't

I have an MBR formatted sd card and when connect to a Linux machine (xubuntu 12.04) it can mount a partition and parse the file system (as can GParted). However, when I try to read the MBR from the ...
7
votes
3answers
14k views

Should I use fdisk for partitioning or GPT aware tools?

Question: Should I use fdisk when creating partitions? Or is it advisable to use parted since it uses GPT? (by default?) And with that I can create partitions larger than 2TB.
7
votes
1answer
10k views

“Warning! Secondary partition overlaps the last partition by x blocks” in gdisk, is it safe to use gdisk here? [closed]

I'm trying to install convert my hard drive into GPT using gdisk, when I run sudo gdisk /deve/disk1s4 I get this: Warning! Secondary partition table overlaps the last partition by 2032668853 blocks! ...
7
votes
2answers
1k views

Determine what program is in my MBR code

I've done a lot of partitioning / dual booting on my Macbook Pro. Right now I have Mac OS X installed along with Ubuntu 12.04, with Grub installed on the Ubuntu partition. I am wondering - what is ...
6
votes
2answers
3k views

How to construct a GPT-only partition table on Linux?

All of the tools I've tried until now were only capable to create a dual (GPT & MBR) partition table, where the first 4 of the GPT partitions were mirrored to a compatible MBR partition. This is ...
6
votes
1answer
1k views

How to understand partition table on hybrid ISO image?

If I inspect an hybrid ISO with tools like fdisk and gdisk, then looks like hybrid ISO has both the MBR and GPT in order to support both the BIOS and UEFI: # gdisk -l /dev/sdb GPT fdisk (gdisk) ...
6
votes
1answer
1k views

Boot FreeBSD in legacy mode on GPT disk

I am trying to install FreeBSD in legacy mode (BIOS) on a UEFI system, since I have an Intel Iris Graphics 6100, which is from Broadwell series and is not supported yet by the intel driver, so I want ...
5
votes
2answers
9k views

Transforming a disk from MBR to GPT

I have a disk with classic MBR and want to transform it to use GPT without data loss. I have seen several more or less useful tutorials, but most of them are dealing with the specific problems related ...
5
votes
1answer
11k views

Remove all traces of GPT disk label

I've got an USB pen drive and I'd like to turn it into a bootable MBR device. However, at some point in its history, that device had a GPT on it, and I can't seem to get rid of that. Even after I ran ...
5
votes
1answer
33k views

Creating EFI bootable GPT partition with gdisk on previous MBR, GPT Damaged

So this is a sister question to my previous one about partitioning for a UEFI boot loader. Parititioning for a UEFI boot loader, can LVM be used? Disclaimer: I don't give a flip about the data on it....
5
votes
1answer
214 views

Where is partitions in MBR?

I found lot of examples of MBR records on various systems, and they all have same structure, for example - as here. So - first 512 bytes must have a Code area, Disc signature and Table of partitions. ...
5
votes
1answer
3k views

Overwritten MBR: Is partial/complete recovery possible?

I have a Sony VIAO laptop setup as dual boot (Ubuntu 12.10/Windows 7). Since I wanted to try Archlinux, I installed VirtualBox in Ubuntu. To create a bootable USB stick (from the ISO image on my hard ...
5
votes
1answer
2k views

Can I change an existing partition from MBR to GPT?

I needed to add extra 2.5TB to the existing 400GB disk (sda) on my system. I added new virtual disks with 2.5TB (sdb), proceeded to create the partition table with fdisk. Used pvcreate /dev/sdb1, to ...
4
votes
2answers
1k views

How to create MBR partition /dev/ nodes FreeBSD for mounting

I currently have FreeBSD version FreeBSD 10.0-RELEASE. Installed using a ZFS root. I'm attempting to mount a MBR partitioned drive but I can't get the partition nodes, /dev/ada4p1, etc. The partitions ...
4
votes
1answer
2k views

fdisk, dd, and the Rapsberry pi

I was trying to wipe my 4GB SD card which acts as the hard drive for the Raspberry Pi, so I went into Mac OS X Disk Utility* and Erased the entire disk, and specified that the whole disk be one big ...
4
votes
2answers
13k views

Copy MBR and boot partition to a smaller disk

I'm using a 32GB SD card for my raspberry pi. I have successfully transferred the operating system (Archlinux ARM) to a usb harddrive. Which means that I only need the boot partition on the SD card. ...
4
votes
0answers
323 views

Should isohybrid work on all iso media, fx Windows 7?

I have a an original Windows 7 Professional x86 iso file, straight from Microsoft. I want to make a bootable USB from this ISO. Some sources suggest that I simply dd the iso to the USB, but I don't ...
4
votes
0answers
571 views

backup and restore whole disk

I am using iMac, with GPT and Hybrid MBR partition table. the GPT layout is: EFI partition.(FAT32) Windows 7 partition.(NTFS) MacOS partition.(HFS+) Linux.(ext4) data.(exfat) the hybrid MBR is made ...
4
votes
1answer
2k views

Can't restore/reformat my USB flash drive after moving to GPT

I have 8GB flash memory stick. Sometimes ago I formatted it to be able to install Windows from it. I can't remember what exactly I did but I think I wanted to be able to install Win 7 64-bit to boot ...
3
votes
2answers
2k views

Where to find the VBR on the /dev/sda1 partition?

I have one built-in hard disk /dev/sda which looks like this: Disk /dev/sda: 160.0 GB, 160041885696 bytes 255 heads, 63 sectors/track, 19457 cylinders, total 312581808 sectors Units = sectors of 1 * ...
3
votes
1answer
89 views

Partition table consuming 32K of data?

I create a file of 100MB size, and using losetup assign it to /dev/loop0. Consequently I use fdisk to create an empty DOS partition table, and a new partition that spans the entire disk. One thing ...
3
votes
2answers
265 views

Lost everything after using install-mbr

I was dual booting Windows 8 and BackTrack5 but I erased the MBR while using easyBCD. So I tried this… sudo install-mbr -i n -p D -t 0 /dev/sda1 /dev/sda1 was the primary partition in my ...
3
votes
2answers
19k views

GRUB menu doesn't appear after Ubuntu install alongside with Windows 10

I shrunk Windows partition, freed 100 Gb, installed Ubuntu into it, installed GRUB into into MBS of the first drive and after reboot I got Windows and with no any option to select. Even in BIOS in ...
3
votes
1answer
2k views

Temporarily disabling/uninstalling grub in a dual-boot setup and then restore grub to the state it was at the start

I'm using a dual-boot setup with grub 2.02-beta2 which allows me to switch between Windows 7 and arch linux on a x64 desktop machine. These are both installed on my C: drive on the same physical HDD. (...
3
votes
1answer
4k views

How to dual boot PC-BSD 10.3 (with zfs file system) and debian 7 (crunchbang) using grub2 boot loader in MBR?

I want to dual boot PC-BSD 10.3 with ZFS as the root file system (the only file system) with Debian 7 (crunchbang linux) with ext4 using grub2 boot loader installed in MBR and grub is managed by the ...
3
votes
2answers
1k views

Copying OS from one drive to another migrating from MBR to GPT - what to watch out for?

I'm looking at replacing my current MBR-partitioned 2 TB system drive with quite possibly a 3 TB drive. Copying the files should not pose a problem, but are there any gotchas to watch out for, ...
3
votes
2answers
5k views

How to restore GRUB after windows XP installation?

After I've installed windows xp for dual booting, I need to restore grub of my archlinux installation. I did it a lot of times with windows 7, but this time heavens decided to torture me. I have ...
3
votes
2answers
1k views

Why is GPT recommended for UEFI

3rd time re partitioning my 1TB SSD so hoping to get it right. Learning but still many questions Because my system has UEFI firmware and already have a SSD dedicated to Windows my understanding is ...
3
votes
1answer
1k views

Converting MBR to GPT because of dual-boot

yesterday I installed debian on my system. It all went relatively smooth and nice. Today I decided to install Windows 10 alongside Debian. Unluckily W10 wants a GPT partition table, and Debian ...
3
votes
2answers
1k views

How can I boot DragonFly BSD (HAMMER) with GRUB 2 on a MBR disk?

There is a box with one MBR-partitioned disk. It has four primary partitions. On those are: Windows DragonFly BSD (using UFS2) Linux DragonFly BSD (using HAMMER) Chainloading ...
3
votes
1answer
586 views

Can't format HDDs and install linux to Dell hybrid ultrabook

I've tried installing OpenSUSE 13.2, Debian 8/8.1 and Ubuntu 15.04 (all them amd64). Debian/Ubuntu won't show disks and OpenSUSE can't format the partitions created on them. During the install, ...
3
votes
1answer
19k views

How to use os-prober to find MS-Windows boot data?

I saw Dual boot - Installed arch and windows entry disappeared on grub and I have the same/similar problem. I have Grub and it shows only Debian setup and not MS-Windows. I also tried the following ...
3
votes
1answer
4k views

How to move GRUB installation to a different partition?

I have a laptop for work. I originally had Windows 7 on it then I installed Linux Mint 17 to dual boot. During my installation of Mint 17 I accidentally installed GRUB on the wrong partition (sda2). ...
3
votes
1answer
546 views

How to detect if the FreeBSD disklabel is on the first sector of the disk?

I have attached a FreeBSD disk to my Linux machine. How to detect if the disklabel(aka bsdlabel) is on the first sector of the disk or the PC MBR is on the first sector of the disk and disklabel is ...
2
votes
3answers
7k views

MBR size is 440 bytes or 512 bytes

I remembered reading one question how would you back up the MBR of a disk. Two of the choices are dd if=/dev/sda of=/dev/sdb bs=512 count=1 dd if=/dev/sda of=/dev/sdb bs=440 count=1 and the ...
2
votes
2answers
528 views

Advantage of GPT over MBR partition table [closed]

What is the difference between the GPT and the BIOS disc partitioning systems? when boot drive is below 2TB on a BIOS system or UEFI boot disabled grub on BIOS system with GPT partitioned needs an ...
2
votes
1answer
10k views

fdisk: partition contains a ntfs signature. remove it?

I'm installing NixOs on a ThinkPad X220. Though I'm very comfortable in the shell, it's the first time I've set up my own system, and I'm running into some unknowns while trying to partition the hard ...
2
votes
2answers
6k views

Changing from MBR to GPT

I'm trying to completely remove linux from my machine to make way for Windows, but to do that I need to change my disk type to GPT instead of MBR. I have a bootable usb with Ubuntu on it that I can ...
2
votes
2answers
523 views

alignment of extended partitions

I read an article on aligning file-systems on partitions and this said that: When manipulating MBR disks, be aware that the alignment of extended partitions is unimportant. These partitions hold ...
2
votes
3answers
2k views

What information is stored on the gap before the first partition?

Partitioning tools(for example fdisk) tend to leave a 2047 sector(LBA 1-2047, 1048064 bytes) between the MBR and first partition. On LBA 0 there is a MBR and from LBA 2048 starts the first partition. ...
2
votes
2answers
583 views

How does system know where the first logical disk starts?

I'm trying to understand the ms-dos partition table, and there's the following diagram: It comes from this site. Almost everything is pretty clear to me, but there's one thing I don't get. As you can ...
2
votes
2answers
408 views

Can I safely resize my partition from its beginning?

Currently dual booting Windows 8 and Linux Mint 14, sooner or later I will give more space to my Linux system. Is resizing my Linux partition from the beginning a safe operation ? If yes, could you ...
2
votes
2answers
55 views

How to determine if a PC has a combination of GPT disk and legacy BIOS boot, where the boot code is read from the MBR?

In a comment, Johan wrote: In the rare combination GPT disk + legacy BIOS boot, the boot code is read in the old-fasioned way from the MBR What is the proper way to determine if a PC has the ...
2
votes
4answers
3k views

Are there extended partitions in GPT partition table?

Under the MBR model, we could create four primary partitions one of which could an extended partition that's further subdivided into logical partitions. Consider this GPT schematic taking from ...
2
votes
1answer
13k views

Using dd in order to save and restore a boot sector?

Through some legacy code I'm using dd to save and restore (parts) of a bootsector after unzipping the .iso of the system onto the hard drive (from a live cd). I use the following command to save the ...