Components

Selecting a hard disk partition in uefi. System reserved disk: how to remove it, why it is needed, where it comes from

System partition (EFI or ESP system partition).

The computer must contain one system partition on the disk. On EFI and UEFI based systems, this partition is called the system partition EFI or ESP. This partition is usually stored on the primary hard drive. The computer boots from the system partition. This partition has a minimum size of 100 MB and must be formatted using the FAT32 file format. This partition is managed by the operating system and should not contain any other files, including the Windows Recovery Environment tools. The standard disk configuration in GPT layout on a UEFI system is shown in fig. one.

Rice. 1.An example of the configuration of disk partitions on a PC with UEFI.

An EFI partition (ESP) formatted in FAT32 is required for GPT partitioning on UEFI systems. The standard size of an EFI partition is 100 MB, but on 4K Native extended format disks (4KB sectors) it is increased to 260 MB due to FAT32 limitations. PC manufacturers may store some of their tools on this partition, so its size varies depending on the manufacturer.In GPT partitioning, the EFI partition performs one of the roles assigned to the System Reserved partition in MBR partitioning. It contains the Boot Configuration CD (BCD) store and the files needed to boot the operating system.

Main p principles of building and functioning of a file system based on FAT-32.

1) Each element of the FAT table (starting from the second one) corresponds to a cluster in the data area with the same number.

2)Number file initial cluster indicated in catalog line The that defines the File. Thisroom is also a link to an entry in the FAT table that contains room next file cluster,and is a link to the FAT table entry that contains the number of the next file cluster etc.

3) A cluster is a continuous sequence of sectors (fixed size). This is the addressable "chunk" of the file.

4) Code in FAT table element can still determine free cluster, defective cluster and end-of-file sign.

5) File in the FAT section - is a sequence of clustersspecified usingdirectory strings and elements of the FAT table.

6) All operating systems can work with a FAT-32 partition (the main factor in the use of FAT-32 in ESP).

As a result high-level partition formatting, writing system information to the data blocks of a seriesinitial sectors of the partition, is created logical drive (volume) file system type FAT32, which consists from three main areas( rice. 2) , in the following order:

- "reserve" area (region of reserve sectors);

- area of file allocation tables (FAT1 and FAT2);

- area of files and directories (data area).

Root directory stored in the data area as regular file and can expand as needed.

Most Windows 7 installations include tiny 100 MB partitions called `system Reserved', also known as MSRs or "Microsoft System Reserved" partitions. For the rest of this article, I will refer to this section as MSR for brevity.

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Note: Some OEM installations may have this section titled `system` or even `recovery`. In either case, this will be the `Active` partition on the same drive as the `C` drive.

Do I have an MSR partition?

Some OEM Windows installation 7 do not include the MSR section. To check if you have this partition, run Macrium Reflect and find the partition on system drive called `System Reserved'.

Note: If the `C` drive is your `Active` partition, you just need to do backup and restore disk `C` for full recovery systems.

What does the MSR section do?

The MSR section handles the second stage of the boot process after the Master Boot Record (MBR) . The MBR is located on the first sector of the disk and is loaded at system startup, after booting, control is transferred to the boot sector code section of the active partition, this is the MSR partition if it exists on your `C` drive. The MSR contains the `oot` directory containing the Boot Configuration Data (BCD) . BCD controls the next step in the boot process and loads the operating system from the C: drive. The MSR partition is always the `Active` partition on the system drive, and must be set to the `Active` partition. The contents of this partition will not change, and by default, no drive letter is assigned in Windows, so you cannot change it.

Do I need his image?

The image in the MSR partition is necessary to restore your system in order to move the system to new disk. However, if you only need to update the system to an earlier date, the MSR recovery partition is not needed, you just need to restore the C drive. This is necessary to restore the Windows 7 partitions to the same location for the BCD to still be able to reference them while loading. If you are restoring to a new or unformatted drive and then going to primary disk C as "primary". The simplest solution is to use DiskRestore to restore both partitions at the same time. DiskRestore - available in the Windows PE CD rescuer and can be run from BartPE if you are running the free edition of Macrium Reflect.

Summary

You must create at least one image on the MSR partition if it exists on your system. However, the partition will only take up 100 MB and it is only a small amount to have an image of the entire image of your `C` drive.
If you want to restore your system to an earlier point, then you just need to restore the `C` drive (as "primary" not active), then there is no need to restore the MSR partition.
If you are restoring your system to install it on a blank or unformatted drive, then you should first restore the MSR partition as the "active" partition, then restore the `C` drive as primary .

So this is a sister question to my previous question about partitioning for the UEFI bootloader. Deviation for UEFI bootloader, it is possible to use LVM?

Disclaimer: I'm not talking about the data. Windows 8 can die in a fire.

Following the instructions, I have one 400MB device that I believe was previously a Microsoft Reserved partition (I believe it's an MBR partition?). Before I knew what I needed to do, I removed the existing partition with the fdisk utility and created an MBR partition with an ext4 file system and rebooted for the changes to take effect.

Then I realized it wouldn't work for a UEFI firmware, a firmware so hipster and awesome that it has to be different in every way. gdisk this time I went into gdisk and looked for partitions and didn't find any. I created new section The GUID on this device is 400MB with the correct EFI code of type EF00. This turned out to be successful, so I created file system FAT32, mkfs -t fat32 /dev/sda1 and that was successful.

I followed all the instructions to install Arch Linux from the bootable installation CD that was downloaded in UEFI mode which I might add. I got to the point where I installed gummiboot on the system and it immediately told me that my sda1 device was not a proper EFI partition. Thoroughly confused, I did a gdisk -l on the device and found that it determined that the GPT partition was corrupted and the MBR partition was still there.

Partition table scan: MBR: MBR only BSD: not present APM: not present GPT: damaged

He then introduced three options: MBR, GPT, or pure GPT. I chose GPT thinking it would remove the MBR partition tables, but that doesn't matter.

Realizing that I still don't and don't know how to create a proper GPT partition from an existing MBR partition, I ran Quick Analyze on testdisk and everything looks good and green. The testdisk utility recognizes this as a valid EFI boot partition in every way.

I'd like to fix the GPT partition if possible so I can avoid all the installation and setup steps starting with my Arch install. If that's not possible and I need to destroy this partition and start over, can I keep the data that was already set here and manually add it back after I've fixed the boot partition?

One Solution collect form web for “Creating EFI bootable GPT partition with gdisk on previous MBR, corrupted GPT”

Ubuntu UEFI Community Wiki notation. The same rules apply regardless of distribution.

Creating an EFI Partition

If you are manually partitioning your disk in the Ubuntu installer, you will need to make sure you have an EFI partition set up.

If you already have an EFI partition on your drive (for example, if your computer has Windows8), it can also be used for Ubuntu. Don't format it. It is highly recommended to have only one EFI partition per disk.
An EFI partition can be created with latest version GParted (the version of Gparted included in the 12.04 disc is fine. Note: I have included a link to the GParted LiveCD) and must have the following attributes:
- Mount point: /boot/efi (note: it is not necessary to set this mount point when using manual partitioning, the Ubuntu installer will detect it automatically)
- Size: at least 100Mib. Recommended 200MiB.
- Type: FAT32
- Other: The "boot" flag is required.

See this screenshot which will give you an idea of the layout. (Notice /dev/sda1 , I apologize for relying on Ubuntu snapshots again.) You can create this partition by resizing your arch if necessary. This is also a layout for OSX, so if you want dual boot with Win8, you would merge sda2 and sda3 from the screenshot below into 1 ntfs type partition and then sda4 , sda5 and sda6 would be used for Arch.

As for LVM

I believe LVM can be used, but experience will dictate that the EFI partition and mount point you create cannot exist within a volume group and should not exist as a volume. To keep your EFI partition "clean", create a partition that is not part of any LV.

When we install Windows on an empty (untagged) HDD or a partition formatted in the usual way - using the installation media, we don't have to worry about creating EFI- markup operating system. All necessary sections, in particular, boot EFI, are created automatically when the computer is in BIOS UEFI. But if Windows needs to be installed in a non-traditional way.

And on another hard drive with its own independent bootloader, if there is a question of restoring the system to working capacity after removing the hard drive with the boot partition, in such non-standard situations, manual work will be required.

Windows on the second connected to the computer GPT- the disk is not installed with its own EFI-structure. During a normal installation from the installation media, the bootloader of the second system is registered on an existing one. EFI-partition - the one that is on the first disk.

What makes the second Windows vulnerable is that it will not be able to exist on its own if the boot loader of the first system is damaged. Or if it fails or the first hard drive is simply disconnected. To have second Windows had its own independent EFI- markup, at the time of its installation, you need to make the first system invisible - disable its carrier in the settings BIOS, if possible, or by hardware. This is not always convenient, and sometimes impossible in the case of laptops.

The second Windows with its own independent bootloader can be installed by programs running in the environment of the current system, such as or WinToHDD. But they will require you to specify the boot EFI-chapter.

Creating one on an empty hard drive is very easy.

1. Create an EFI partition on an empty hard drive on the command line

So, we have initialized as GPT media without markup and data.

We launch command line.

Be sure to do this as an administrator.

Enter in succession:

diskpart lis disk sel disk 1 (instead of 1, specify the number under which the hard disk you need is listed above) creat par efi size=100 format fs=FAT32

lis disk

sel disk 1 (instead of 1, indicates the number under which the hard disk you need is listed above)

create par efi size = 100

format fs=FAT32

In the disk management utility, we see that the second hard drive has EFI- section on 100 MB. Now we can form a regular section to indicate it to programs like or WinToHDD as system partition WITH .

2. Creating an EFI partition on an empty hard drive with the Bootice utility

Who doesn't love the command line to create EFI-blank media markup can use the utility with GUI. It is free and can be downloaded from any software portal on the Internet. In the main window, select the second hard one. Click .

Then - "Repartitioning".

First of all, check the box GPT in the column "Partition table type". Then tick the box "Create ESP partition". And at the top in the graph "Settings" remove all values Size except the last. We press "OK".

As a result, we get a disk layout with EFI- section on 128 MB and a partition containing the rest of the disk space.

But what if the hard drive is not empty? If it has a structure and stored user data. Or we want to restore Windows that has lost its boot EFI-partition after the failure or disconnection of the hard drive on which its bootloader previously existed. And there are solutions for this. To restore a system without a bootloader, we naturally need an environment to perform certain operations. In one case, a regular Windows installation media will do. Otherwise, we will work with a disk space manager, so we need a functional and reliable LiveDisk WinPE. One of these is LiveDisk Sagittarius. Image download site - Sergeistrelec.Ru .

Note: the following operations cannot be performed on disks dynamic type . The disk of the Windows mirror left without a bootloader must first be converted to the basic type. This can only be done using third party tools.

3. Creating an EFI Partition at the End of Windows

So, we have, for example, the second Windows, which has lost EFI-loader after a disk failure with the first system.

How to run it? The simplest and fast way- create EFI-partition at the end of the system partition and recreate the bootloader. You don't need anything more than the command line to do this. We boot from the Windows installation media, immediately press Shift + F10. This combination will launch a command prompt. If we use LiveDisk Sagittarius, we start, respectively, from it.

And already on board we use the command line.

In it we enter:

diskpart lis vol sel vol 1 (instead of 1, specify the number under which your partition with the system appears above) shrink desired=100 creat par efi format fs=FAT32

Here is the specified section shrunk to 100 MB and in the vacated place was created EFI-chapter.

Now we can recreate the bootloader.

On the command line, exit :

That's it - Windows has been restored.

4. Creating an EFI Partition Before Windows

The boot partition usually exists at the beginning of the disk, before the system partition. It doesn't have to be this way, but it's done to speed things up. Windows startup. To UEFI found the bootloader. On the SSD such optimization is unlikely to be tangible, but in the case of HDD you can compete even for a fraction of productivity.

On board LiveDisk Sagittarius we start . We make a click on the system partition, on the sidebar of operations, click "Change of size".

Slightly pull the slider on the map to the right so that in the column below "Unallocated space in front" several MB. Next, instead of the drawn figure, we enter 105 . To make it work 105 MB. We press "OK".

As a result, the program will release the correct amount of disk space, in our case 102.01 MB. And leave a little tail at the back of the section. We press.