Uefi Và Legacy
Teena Ruiter
In general, install Windows using the newer UEFI mode, as it includes more security features than the legacy BIOS mode. If you're booting from a network that only supports BIOS, you'll need to boot to legacy BIOS mode.
You might see separate commands for the same device. For example, you might see UEFI USB Drive and BIOS USB Drive. Each command uses the same device and media, but boots the PC in a different firmware mode.
Some devices only support one mode (either UEFI or BIOS). Other devices will only allow you to boot to BIOS mode by manually disabling the UEFI security features. To disable the security features, go to Security > Secure Boot and disable the feature.
Some older PCs (Windows 7-era or earlier) support UEFI, but require you to browse to the boot file. From the firmware menus, look for the option: "Boot from file", then browse to \EFI\BOOT\BOOTX64.EFI on Windows PE or Windows Setup media.
If you want to ensure that your drive boots into a certain mode, use drives that you've preformatted with the GPT file format for UEFI mode, or the MBR file format for BIOS mode. When the installation starts, if the PC is booted to the wrong mode, Windows installation will fail. To fix this, restart the PC in the correct firmware mode.
If you want a PC to only boot into a certain mode, you can remove the files that Windows PE or Windows Setup use to boot in UEFI or BIOS mode. Remove the following files, depending on the mode you want to boot to.
Secure boot, which is under Security, is disabled (I've heard that it should be disabled if you want that option). Still, I can't find the option to change the boot mode, so I'm not sure what that means.
Do I have to change another setting for it to appear? Do I only have one boot mode? In that case, how may I find out which one I have? Do I have both but can't change it in the BIOS? In that case, can I still change it in some other way?
So it's possible that some firmwares offer "both UEFI & legacy" as their only mode of operation (that is, both the UEFI support and the BIOS compatibility parts are permanently active). This is less common in new systems, where disabling legacy boot allows for a lot of optimizations, but used to be quite common in older systems.
The fact that you have Secure Boot as a configurable option confirms it: it is impossible to have Secure Boot without UEFI. On some systems, enabling Secure Boot will also lock out/disable/hide legacy boot options, enforcing UEFI boot only. But back in 2013, designing an UEFI-only x86 system without legacy BIOS compatibility would have been an odd choice.
If there is indeed no way to choose a "UEFI only" or a "legacy-only" mode, you must be extra careful when booting your OS installer: if the installation media is compatible with both UEFI and legacy BIOS boot, you should see two boot options for that media, one with UEFI and the other without. You should choose the boot mode of the OS installer to match the intended boot mode of the OS installation.
Note that the "UEFI/legacy/both boot modes allowed" selection does not necessarily have to be in the Boot section of the BIOS menus (although that would be a sensible place for it). It might also be buried deep somewhere in the "advanced options" section.
Do you see your the Boot Option Priorities on your screenshot? It shows 7 devices, some UEFI and some not. The same physical devices are listed more than once, because you have the option to boot them as UEFI or as Legacy.
it depend options offered by Bios firmware, Some Large integrators Like Lenovo unfortunately followed intel and Microsoft recommandations for security raisons and have deleted CSM & Legacy Modules ! but mainly have Phoenix's Technologie Bioses. you do have Megatrends one, i think it offers you more optionsOddly Some modern models still have it though
Disable first Secure BootThen go to the last tab (Startup) you should find there the "OS Optimized defaults" option in "Load Setup Defaults" , disable it ! then return to Boot Tab you should see the Uefi/Legacy appears
Now that i'm comfortable with OMV, I want to do a new installation on my actual NAS box. It's a couple year old Dell i5 system that has UEFI enabled by default in the BIOS. My test machine that i've been using was older and only had legacy. Does it matter which one I use or should I go in to the BIOS and change from UEFI to legacy on my actual server before I do the installation?
Thank you for the information. This is all new to me but boy has it been fun learning new things. I still don't know how much of the capabilities of OMV I will use, but it's nice to know I have a place to go to for help if I expand my usage.
On an UEFI system you need to switch to 'Legacy' if you want to install directly OMV's ISO (the ISO doesn't support UEFI boot for reasons unknown to me). If you don't want this or your UEFI doesn't support legacy mode you need to install Debian 9 first and then OMV in a second step: UEFI boot manager: can't install OVM from a USB-stick on Apollo Lake mini-pc
While I know some facts about UEFI and Legacy and basic differences between them, like UEFI allowing for faster booting (I've checked this question already, but it doesn't answer mine), I have a bit of a different question(s):
I'm not sure if BIOS settings can have any influence on how the system works and if legacy settings can be the cause of hardware misbehaving, but I usually install my Linux systems in legacy mode, with boot priority legacy first. Is it ok this way or should I change either the boot priority to UEFI first, or everything adjusted to UEFI (this Lenovo G50-45 laptop came with Windows 8).
Also, on my laptop quite a few things don't work properly, whereas on Windows everything worked and I'm not sure where the fault lies. I only recall, that Windows wouldn't install with legacy settings, I had to change boot priority to UEFI first to be able to install it (Win 7 Ultimate x64).
Currently on *ubuntu (any variant) 15.04 I have issues with microphone not working (distorted, very weak sound) and Xorg crashes my entire session with Libreoffice in k3.19+. Tested with many distributions.
So, to conclude, which one is recommended for a flawlessly working system? Do Linux distributions work better with Legacy, or UEFI? (if there is any difference in terms of functionality of the system)
For most hardware, the boot mode (EFI vs. BIOS) is irrelevant. The drivers Linux loads are identical in either case, as should be the performance. The main caveat here is that the hardware may be initialized in different ways depending on your boot mode, and if the Linux drivers make assumptions about how the hardware is initialized, one way or the other may work better. This sometimes made booting one mode or the other (usually BIOS mode) preferable in the past, but this type of problem is becoming rather rare today. This type of issue mostly affected video hardware and drivers, but in principle it could affect anything.
In your specific case, my suspicion is that you've got "bleeding-edge" hardware with poor Linux support, or perhaps hardware that requires special configuration to work correctly in Linux. Your best bet is to post separate questions about each specific device that's not working to your satisfaction. You can also test with both BIOS-mode and EFI-mode installations to determine empirically which one works better for you, since there is no way to accurately generalize which mode is best.
You also will have problems with using certain tools which cannot deal with GPT (the only improvement from bios to uefi is support of GPT, everything else is disadvantages and there's many of them). It's not that much of a problem if you use GPT on an external or secondary HDD, but don't boot from it.
If you don't have an HDD bigger than 2 TiB to boot from, there's no problem in the first place. If you do have an HDD with more than 2 TiB to boot from but don't need to have a partition bigger than 2 TiB and don't need to have the beginning of a partition after the first 2 TiB, you also don't need GPT and therefore no UEFI. (So having a 4 TiB HDD with some partitions in the beginning and the last 2 TiB filled with 1 2 TiB is fine and works without GPT.)
As already stated above: This only is about the HDD you boot from. If you have an SSD for booting (which of course can't be that big because such big SSDs don't exist) and only want to use GPT for data storage, that's all fine and you don't need UEFI to access them.
For example, the "automatic" firmware upgrade, that is integrated in the Gnome software manager requires UEFI. No UEFI means firmware upgrades via LVFS/ fwupd / fwupdmgr will not work. Which, in most cases, means no firmware upgrades on Linux, at all.
I followed the Petri guide for setup ( Part 1 , Part 2 , Part 3 ) and within MDT currently have a single image created from a vanilla Windows 10 Pro ISO, with a single task sequence, that was left pretty much with defaults.
PXE booting with UEFI works great; the imaging process works as expected and I am left with an activated, domain joined installation. But when legacy booting, it looks like the process is going well but it fails with errors. BDD.log contains:
Due to code changes in Windows ADK 10 v2004 the MDT utility (Microsoft.BDD.Utility.dll) that detects BIOS or UEFI firmware types no longer works correctly, and detects BIOS-based machines as UEFI-based machines. Update June 3, 2020: Microsoft...
Hello!
I have searched a lot, including Arch Wiki articles about GRUB, Boot loaders, UEFI and etc. but still can't decide which one is better and why. Does UEFI has more security implications than BIOS/Legacy? Which one is more likely to avoid problems/bugs and why? The only advantage of UEFI I read is that it boots faster than BIOS/Legacy but that isn't important for me. I know Arch supports both, but which mode is more preferable for Arch? And finally what mode are you using and why?