You can use parted -l to determine the type of partition table. Eg:
$ sudo parted -l
Model: ATA TOSHIBA THNSNS25 (scsi)
Disk /dev/sda: 256GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Number Start End Size Type File system Flags
1 4194kB 32.2GB 32.2GB primary ext4 boot
2 32.2GB 256GB 224GB ...
On linux, you can check this via the gdisk tool which should be available for any distro.
gdisk -l /dev/sda
Here, /dev/sda is the device node of the physical drive, not a partition (/dev/sda1, /dev/sda2, etc. are partitions).
If you see something that includes:
Found invalid GPT and valid ...
That link you posted looks like a very ugly hack type solution.
However, according to the man page, gdisk, which is used to convert MBR -> GPT, also has an option in the "recovery & transformation" menu (press r to get that) to convert GPT -> MBR; the g key will:
Convert GPT into MBR and exit. This option converts as many partitions
Will dd if=/dev/zero of=/dev/sda wipe out a pre-existing partition table?
Yes, the partition table is in the first part of the drive, so writing over it will destroy it. That dd will write over the whole drive if you let it run (so it will take quite some time).
Something like dd bs=512 count=50 if=/dev/zero of=/dev/sda would be enough to overwrite the ...
UUID is a filesystem-level UUID, which is retrieved from the filesystem metadata inside the partition. It can only be read if the filesystem type is known and readable.
PARTUUID is a partition-table-level UUID for the partition, a standard feature for all partitions on GPT-partitioned disks. Since it is retrieved from the partition table, it is accessible ...
Most of the previous respondents are correct when they say that you can usually do what you need with a GPT partition table layout, but since there are valid reasons for wanting to use MBR, I think I will just answer your question instead of assuming you are wrong for asking.
To get rid of the GPT, you need to remember that with this format, there is a ...
I'm going use the term BIOS below when referring to concepts that are the same for both newer UEFI systems and traditional BIOS systems, since while this is a UEFI oriented question, talking about the "BIOS" jibes better with, e.g., GRUB documentation, and "BIOS/UEFI" is too clunky. GRUB (actually, GRUB 2 -- this is often used ambiguously) is the bootloader ...
As the OS was not specified, here is FreeBSD way of doing things.
All is done through the gpart command (short for GEOM partioner - nothing to do with GNU).
A simple gpart show would show you all the available partitions of all the disks, but you can specify the device to have a more precise look on one:
legacy partition layout with MBR (aka "msdos") and ...
MBR, Master Boot Record
Wikipedia excerpt; link:
A master boot record (MBR) is a special type of boot sector at the very beginning of partitioned computer mass storage devices like fixed disks or removable drives intended for use with IBM PC-compatible systems and beyond. The concept of MBRs was publicly introduced in 1983 with PC DOS 2.0.
If you don't want to fiddle with dd, gdisk can do:
$ sudo gdisk /dev/sdb
GPT fdisk (gdisk) version 0.8.8
Partition table scan:
BSD: not present
APM: not present
Found valid GPT with protective MBR; using GPT.
Command (? for help): ?
b back up GPT data to a file
w write table to disk and exit
x extra ...
From what I just found out, it may be unsafe. I was getting this same error
*************************************************************** Found invalid GPT and valid MBR; converting MBR to GPT format in memory.
THIS OPERATION IS POTENTIALLY DESTRUCTIVE! Exit by typing 'q' if you
don't want to convert your MBR partitions to GPT format!
TO ADDRESS YOUR EDIT:
I didn't notice the edit to your question until just now. As written now, the question is altogether different than when I first answered it. The mirror you describe is not in the spec, actually, as it is instead a rather dangerous and ugly hack known as a hybrid-MBR partition format. This question makes a lot more sense now - it's not ...
grub itself does not care about boot flags.
An EFI System partition is distinguished by its GUID type C12A7328-F81F-11D2-BA4B-00A0C93EC93B, not by a boot flag. Yes, this partition needs to be formatted FAT32. Not all FAT32 partitions are EFI System partitions, only one of them, and that one, if present, is small and has a special purpose. On a computer which ...
EFI knows how to access FAT and FAT32 filesystems. This is why your EFI boot partition has to be FAT or FAT32 formatted. EFI however does not know how to read a software RAID 1 partition, even if it is formatted using FAT32. There is a pretty simple away around this, at least using Arch Linux. When installing the system, you set the boot partition up as ...
The partition table is stored near the beginning1 of the (logical2) disk device.
Overwriting that area with anything (zeroes from /dev/zero or any other data) will replace the partition table with gibberish, so it will no longer be obvious where the partitions on the device begin.
One can still scan the whole disk and try to identify the "magic bytes" that ...
From the Arch Wiki:
When creating a partition, parted might warn about improper partition alignment but does not hint about proper alignment. For example:
(parted) mkpart primary fat16 0 32M
Warning: The resulting partition is not properly aligned for best performance.
The warning means ...
The partition unique GUID is generated at the time that the partition is created. It uniquely identifies the partition at least inside the disk and probably among all the disks you own (because it's unbelievably rare for GUIDs to collide).
A partition GUID code (by which I believe you mean a partition type GUID), on the other hand, is a known, fixed GUID. ...
With udisks on Linux:
$ sudo /lib/udev/udisks-part-id /dev/sda
using device_file=/dev/sda syspath=/sys/devices/pci0000:00/0000:00:0b.0/ata1/host0/target0:0:0/0:0:0:0/block/sda, offset=0 ao=0 and number=0 for /dev/sda
Entering MS-DOS parser (offset=0, size=500107862016)
found partition type 0xee => protective MBR for GPT
Exiting MS-DOS ...
A minor correction. As I understand it, GPT disks don't have partition types anymore, they are all "primary". Command 'mkpart primary' doesn't create a primary partition like it does on msdos disks, it just creates a partition called primary. You can just as well use command
(parted) mkpart Parted-FUN! 21476MB 4000787MB
Model: ATA ST4000DM000-...
The accepted answer by @lik shows how you can specify the preferred alignment. However, parted always uses that alignment for checking the resulting partition, but not always creates partitions with that alignment.
TL;DR: When 1MiB is the optimal alignment, specifying 0% will work for disks of 200MiB and bigger. For smaller disks or larger alignment, ...
gdisk only has the one command line option (-l), to list the partition table and then quit. All of the other operations are conducted interactively from within gdisk. See Rod Smith's walkthrough for some more context.
Essentially, though, you want to just use the command # gdisk /dev/sdb and then, at the prompt, use the s command to sort the partition ...
Use gdisk /dev/sda
Note: /dev/sda is in the case of the person who asked this question but change it to your drive name.
Once you are inside with gdisk use:
x extra functionality (experts only)
then when you type p to see all the options, you will see this:
Expert command (? for help): ?
a set attributes
c change partition GUID
d display the ...
Partitioners like to align partitions on a mebibyte boundary these days. For MBR partitioning, there are 4 primary partitions, and for the rest you need extended and logical partitions.
While the layout of the primary partitions is expressed at the end of the first sector of the disk, for the logical partitions, you've got a linked list of additional ...
You cannot use fdisk to work with GPT disks, it will only work with MBR disks. Any disk that > 2TB must be GPT.
You likely cannot mount this HDD because even though the kernel has detected it (in the dmesg output) the HDD hasn't been partitioned or formatted with a filesystem so that it can be mounted.
Try the following to do this:
$ sudo sfdisk -l
That message is normal, if your (virtual) disk magically became larger.
GPT partition table is both at the start and at the end of the disk. It's supposed to make it more resilient against failure.
When you "fix" this issue it will simply re-write the GPT backup header at the new end of your disk. This does not affect existing partitions in any way at all, ...
UEFI has nothing to do with power management. ACPI manages power. UEFI indicates modern firmware than BIOS and newer platform, thus improved power efficiency. This might be a correlation.
The PM subsystem is different from UEFI. Linux includes a whole range of power management functionalities, though unrelated to UEFI, like cpufreq, intel_pstate, pcie_aspm, ...
some unix partitioner, are deperecated and GPT partition table is new and some tools doesn't work GPT. GNU parted is new and gparted is GNOME Parted
root@debian:/home/mohsen# parted -l /dev/sda
Model: ATA WDC WD7500BPVT-7 (scsi)
Disk /dev/sda: 750GB
Sector size (logical/physical): 512B/4096B
Partition Table: msdos
Number Start ...
The fdisk equivalent is gdisk, which is commonly available in the gptfdisk package via package manager. You'd do much better to use it, in my opinion. I don't trust anything *parted, personally - any partition tool that simultaneously partitions and formats is not a partition tool.
Try to align to eMMC erasure block size. It usually equals 0.5, 1, 2, 4, 8 MiB depending on eMMC datasheet. If you find block size alignment too much memory wasting, then stick to the page size, generally found in the range of 4..16 KiB.
Try to make partition sizes and borders a multiple of erasure block size, so when file system writes to the first or last ...