Encrypted partition

hi
i have an encrypted partition use by suse
is there a way to use it with arch linux?
thanks

Generally you would use the same method you (or suse) uses to mount and unlock the encrypted partition.
If you use Luks for the encryption with dm_crypt you could simply run:
cryptsetup luksOpen /dev/hdaX name_of_partition
mount /dev/mapper/name_of_partition /partition_mountpoint
To do all of this atomatically you would need to edit /mnt/etc/crypttab and enter the needed information.
Here are two wiki entries concerning LUKS with Arch, they do not directly relate to what you need but you could use some pieces of it.
LUKS Encrypted Root
RAID Encryption LVM
Most of the above is only valid when you're using LUKS I suppose. I also can't say anything about other methods because I never used them.

Similar Messages

  • Link to a file in encrypted partition

    Hi all,
    I have an encrypted partition with some files I use regularly.  If I mount the partition, I can make a shortcut to files by dragging them onto the dock.  If I click the icon on the dock, and the encrypted partion is not mounted, I get prompted for the password and the partion mounts and the file opens.
    I'd like to put several of these shortcuts in a single folder on my dock.  Just dragging and dropping does nothing.  Any thoughts?

    So I solved this by having an applescipt call a bash script.  Kind of a silly round-about way to do it, but it works.

  • Additional, encrypted partition mounted as /Users

    Recently I removed DVD-ROM drive from my MacBook Pro and installed 60GB SSD for system (in regular HDD bay) and my old HDD instead of DVD drive.
    My plan is to use fast SSD drive for system and the HDD for data.
    I would like to have my HDD partition mounted as /Users so all users' home directories are stored on HDD.
    I read this article: http://www.red-sweater.com/blog/1935/lions-whole-disk-encryption but it seams there is a problem with logging in if the user's home directory resides on separate encrypted partition.
    My question is:
    Is there any chance I can have "fully functional" /Users directory mounted as additional encrypted partition?
    Thanks,
    Mike

    Hi Linc,
    Thanks for your answer.
    No, because the Users volume would already have to be unlocked and mounted before you could log in, and that's impossible.
    I don't think it is impossible. I would reather say: "Apple makes it difficult to do".
    I barely see any problem with mounting other partitions on the system level during boot.
    The question is: "How hard is it to do that now?"
    The second question is: "When (and how) Apple will make it easier?"
    The best you could do would be to log in, mount the volume as root at /Users, then log out and log in again. I wouldn't recommend that you try this.
    Yeah... I don't feel like log in two times. I wouldn't recommend it either.
    I have another idea which is:
    1. Mount addtitional encrypted partition as /Volumes/Whatever
    2. Create directories like:
    /Volumes/Whatever/Documents
    /Volumes/Whatever/Pictures
    /Volumes/Whatever/Music
    /Volumes/Whatever/Library
    3. Mount these directories in places under /Users/MyUser/... during login.
    So there are other questions:
    1. How to do it the "Mac way"?
    2. There are maybe some directories which probably can not be mounted this way as its content can be necessary for login process to perform (probably some subdirectories of Library). Is it the case?
    Cheers,
    Mike

  • Gummiboot and encrypted / partition

    Hi,
    This is my first experience with Arch, with GPT, with LUKS, and with gummiboot, so I have a lot of sources of ignorance. 
    I am trying to set up a LUKS-encrypted system with encrypted swap.  I have followed the beginner's guide and the dm-crypt with LUKS guide pretty carefully and have no problem creating the encrypted partitions.  However, I don't quite understand how to construct the gummiboot entry for booting into the system. 
    the gummiboot wiki page has some instructions:
    An example entry for encrypted root (dm-crypt with LUKS)
    $esp/loader/entries/arch-encrypted.conf
    title          Arch Linux (Encrypted)
    linux          \\path\\to\\vmlinuz-linux
    options        initrd=\\path\\to\\initramfs-linux.img cryptdevice=UUID=<UUID>:luks-<UUID> root=UUID=<luks-UUID> rw
    In the encrypted example, not that the initrd is in options -- this does not appear to be discretionary at this time. Note that UUID is used for in this example. PARTUUID should be able to replace the UUID, if so desired.
    much of this is foreign to me.  In particular, how do I identify the various UUID's:
    cryptdevice=UUID=<UUID>:luks-<UUID> root=UUID=<luks-UUID>
    are those all the same UUID?  Or is there a difference between the plain  UUID and the luks-UUID?  And how do I get either of those pieces of information? 
    also, I am trying to speed things up a little by using this install script from the web:
    https://github.com/altercation/archston … chstone.sh
    however, a bunch of stuff there seems like it's out of date (lots of referenes to rc.conf, for instance!). 
    I'm wondering if there are other inconsistenies as well I should be careful of. 
    Thanks,
    Matt

    yes, this random script was a bad idea and I've stopped using it.  That said, I really don't understand the UUID stuff in my initial question, despite having gone through the beginner's guide & stuff.  In fact, the whole gummiboot stanza is odd to me: 
    An example entry for encrypted root (dm-crypt with LUKS)
    $esp/loader/entries/arch-encrypted.conf
    title          Arch Linux (Encrypted)
    linux          \\path\\to\\vmlinuz-linux
    options        initrd=\\path\\to\\initramfs-linux.img cryptdevice=UUID=<UUID>:luks-<UUID> root=UUID=<luks-UUID> rw
    what is with the escaped windows-looking  backslashes -- shouldn't this read more like:
    title          Arch Linux (Encrypted)
    linux          /vmlinuz-linux
    options        initrd=/initramfs-linux.img cryptdevice=UUID=<UUID>:luks-<UUID> root=UUID=<luks-UUID> rw
    ... and is there a way to find the relevant UUID's somewhere?  Thanks,
    Matt

  • OpenSUSE - Arch switch: encrypted partitions, keeping /home and other

    Hello,
    I am considering switching from openSUSE to Arch -- I want to gain performance, avoid releases and try something new -- but have some doubts/questions. I would appreciate if you could help me a bit with resolving them :)
    i. From what I see on the fora some of you are (ex) SUSE users so... will I miss anything?
    ii. Should I expect any problems in general?
       a) I am using nVidia proprietary drivers and, despite all downsides, would like to keep doing so. Are there any problems regarding installation or keeping them up to date?
       b) Is it possible to use s2ram and s2disk or obtain working counterpart(s), as, I hear, there are some problems with those?
       c) Is it possible to install software from debs and/or rpms? Possibly without extracting and moving files manually?
       d) Is it safe to assume that hardware and all applications not specific to any distribution will work just as well as they do on SUSE? I know, Linux is Linux but still.
    /edit:   e) Does getting fonts to be displayed properly takes a lot of tweaking? This problem does not exist on SUSE but on other distros it used to be a pain.
    iii. I have SUSE installed on encrypted partitions (with luks and /dev/mapper so it's pretty similar to setup recommended for Arch in that matter) and would like to avoid reencrypting as well as keep /home untouched. Is it possible and not too complicated?
    (I have seen http://wiki.archlinux.org/index.php/LUKS_Encrypted_Root, http://wiki.archlinux.org/index.php/Off … tall_Guide and http://wiki.archlinux.org/index.php/Ins … ing_Linux)
    Any additional information and comments are welcome.
    Last edited by skx (2009-02-16 15:36:33)

    quarkup wrote:ii)
    a) No problemo. I use nVidia drivers too for my 6800go, with no issues.
    Inxsible wrote:ii c) [....] I think there are packages in AUR, which can help you convert them to an Arch PKGBUILD and then install them.
    Thanks.
    bgc1954 wrote:i)
    Well, if you used suse for any length of time, you might miss the incredible slowness of yast as compared to pacman. :D
    YaST is not that slow anymore ;)
    What about the encryption part? That's the one that makes me anxious.
    Last edited by skx (2009-02-16 15:50:58)

  • Can not encrypt partition

    Hello.
    I'm trying to set up an encrypted system and followed an entry in the german arch user wiki.
    I have partitioned my harddisk in 4 partitions, but sadly got an failure with the first command
    When i enter
    cryptsetup luksFormat /dev/sda3 cipher aes-cbc-essiv:sha256 verify-passphrase --key-size 256
    i get this message
    cryptsetup: Unknown action.
    I'm able to tab cryptsetup so it should be on my install disc.
    Does anyone know how i could solve this problem?
    Thanks in advance

    cryptsetup luksFormat /dev/sda3 --cipher aes-cbc-essiv:sha256 --verify-passphrase --key-size 256
    The -- were missing. Please edit the wiki entry.
    hightower
    Last edited by hightower (2007-06-19 20:57:16)

  • OS X won't boot after being installed on an encrypted partition

    Hello!
    Today i formatted my entire disk, but made it Journaled, Encrypted. It installed (actually "downloaded aditional files"), and then booted with a cross/do not proceed sign. I booted from the install disk again, got an error telling me to reinstall OS X. I was never asked for my password, and when i started disk utility, the disk was locked.
    Why is the option there if it doesn't work?
    Andrei

    Thanks for this info:
    Kappy wrote:
    There may be many reasons why it didn't work but without knowing exactly what you did it's pretty difficult to make any presumptions.
    Others use it, and there have not been too many posts about using encrypted disks and FileVault 2. But searching the forums may help you.
    One thing I'd consider trying if you were willing to take the time and trouble:
    Drive Preparation
    1. Boot from your OS X Installer Disc. After the installer loads select your language and click on the Continue button.  When the menu bar appears select Disk Utility from the Utilities menu.
    2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Note the SMART status of the drive in DU's status area.  If it does not say "Verified" then the drive is failing or has failed and will need replacing.  SMART info will not be reported  on external drives. Otherwise, click on the Partition tab in the DU main window.
    3. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed.
    4. Select the volume you just created (this is the sub-entry under the drive entry) from the left side list. Click on the Erase tab in the DU main window.
    5. Set the format type to Mac OS Extended (Journaled.) Click on the Security button, check the button for Zero Data and click on OK to return to the Erase window.
    6. Click on the Erase button. The format process can take up to several hours depending upon the drive size.
    Step 1 can be changed to whatever method you are using to boot into the Lion installer or a Recovery HD volume.
    But as ai said, i don't need it. I'm aleadry installing it normally.
    So no need to help. I'm just curious why the Encrypted option isn't working.
    Thia is what i did:
    Booted from the disk, selected my HDD, clicked erase and selected "HFS+ extended (Journaled, Encrypted)"
    It installed
    After rebooting, it didn't ask me for the password i set for encryption.
    Booted with the Cross (X) instead of the logo.
    And that's it... I've seen that if you turn on filevault, it'll ask you for a password when booting. But for me it didn't.
    RIght now it's working (i used the :HFS+ Extended (journaled)" without encryption.
    And i want to know if it's my fault, or Apple's.

  • [Solved]Mount windows encrypted partition

    Hi,
    I have encrypted the Windows 7 system partition fully using truecrypt. In Linux when i try to mount that partition [/dev/sda1] it says "incorrect password of not a truecrypt partition". I am entering the same password which I use while booting into Windows, that is pre-boot password.:/
    Last edited by sHyLoCk (2010-06-15 14:12:53)

    Do you use the same truecrypt version on windows and linux? also to be able to mount encrypted systems you have to activate a separate checkbox telling that the partition is using system encryption in truecrypts mount dialog (don't know where exactly it is since I didn't use truecrypt in a while), otherwise it will show the error you mentioned.

  • How to mount encrypted partition

    I have Archlinux installed in dual boot with Ubuntu. My home partition on Ubuntu is encrypted with ecrypt. I would like to have this partition mounted on boot at Archlinux too. Does anyone can help me how to do that?
    Thanks a lot.

    https://wiki.archlinux.org/index.php/Sy … h_eCryptfs
    Please search the wiki before asking for help here.

  • New encrypted partition? how?

    Hi there!
    I'd like to have seperate partition (encoded one), so that I have to enter password to mount it (like using truecrypt).
    Can mac vault accomplish this?
    And first of all - how to create a new partition without loosing data? I know there are few programmes that can do it, but none of them is free...
    And even if I decide to loose everything and install MAC OS from scratch, can I create few partitions?
    Thanx
    Adam M

    hi myscichu,
    Hi there!
    I'd like to have seperate partition (encoded one), so
    that I have to enter password to mount it (like using
    truecrypt).
    Can mac vault accomplish this?
    i don't use file vault, but Disk Utility can do this. it's simple
    to create an encrypted disk image. put whatever you want
    on there, make some aliases of those things
    on your desktop as appropriate, then close the image.
    now when you dbl-click on one of those aliases, a password
    dialog pops up, and when you enter the right password,
    the image mounts and the alias resolves and starts whatever
    you wanted it to in one fell swoop - just as if that stuff
    was anywhere else on your machine...
    And first of all - how to create a new partition
    without loosing data? I know there are few programmes
    that can do it, but none of them is free...
    i have done that kind of thing a few times, and IMHO it's
    not worth the convenience. the drives ran slower so nowadays
    when i (rarely) want to resize a partition, i totally back up (clone
    actually, using the app Super Duper), scorch the whole drive,
    then repartition, then reinstall from the clone... this is really
    the "right" way to do s'th like this.
    And even if I decide to loose everything and install
    MAC OS from scratch, can I create few partitions?
    of course, see again Disk Utility.... good luck, cheers
    Thanx
    Adam M

  • How to shrink an LUKS encrypted partition?

    Alright, so I have this external hard drive with 1TB. I created 1 partition on it which spans the whole drive. Then I luks-encrypted this partition and put an ext4 filesystem on it. Now I need to make a second partition on it (~8GB). So how would I accomplish this without data loss?
    I googled, but only found information about lvm-setups. In this case I don't use lvm.
    Should I first resize the partition using fdisk and then somehow tell luks that the partition got smaller and last but not least resize the ext4 fs inside?
    Could somebody help me out?
    Edit: Alright so this is definitely the wrong way. I think first resizing the ext4 partition, then the partitiontable and then the luks should do the trick. Will try out and then report back.
    Edit2: Alright this worked without problems.
    Last edited by Watermel0n (2010-07-02 10:21:15)

    I'd like to resize 2 LUKS partitions, so I'm wondering what did you do after resizing ext4 filesystem. I think you used resize2fs for the first step, but I don't know how you resized the physical partition without deleting/recreating it.

  • Grub, UEFI, and encrypted partitions

    I followed the tutorials on the Wiki regarding setting up luks encryption over LVM which worked fine. Part of this process involved getting grub to decrypt the root partition, which also worked. However, I later went and followed instructions for getting UEFI boot to work; I created a separate /boot partition, used grub-install, etc. I'm now in a weird state, though: grub is still using (and unlocking) the root partition and using whatever is in its /boot directory when it really should be using the /boot partition. I've managed to confuse myself enough through all this that I'm not sure what config files and commands I need to mess with to get grub to load the initramfs from the actual boot partition while not also screwing up the root partition that should be unlocked/mounted by systemd.
    My common sense tells me that the latter has nothing to do with the former but it took me long enough to figure out the hack of copying everything in the boot partition to root's /boot just to get the thing booting again after a kernel update that I'd rather just ask here

    tcdavis wrote:I'm now in a weird state, though: grub is still using (and unlocking) the root partition and using whatever is in its /boot directory when it really should be using the /boot partition.
    UEFI and a dedicated /boot partition are separate things, and they are not dependent on one another. The problem is most likely coincidental.
    Make sure your "root=" and "cryptdevice=" kernel parameters are correct. Edit /etc/default/grub, and use the UUID of the LUKS container on the new /boot partition, replacing the old UUID of the root filesystem. This should be the UUID of the LUKS container itself, not the filesystem contained within it. Use `cryptsetup luksUUID /dev/sda2` substituting sda2 with your /boot partition. This only applies to the kernel and is not directly related to GRUB, so it's just a precautionary measure.
    Make sure /boot is mounted, and regenerate grub.cfg:
    mount /boot
    grub-mkconfig -o /boot/grub/grub.cfg
    Delete the contents of /boot on the root partition to prevent confusion:
    umount /boot
    rm -r /boot
    mkdir /boot
    mount /boot
    Also make sure your /boot partition is being mounted (via crypttab and a keyfile) automatically at boot, or you will run into problems later on.
    Strike0 wrote:If you, in your first attempt, installed grub to the MBR and your bios is set to dual legacy/uefi, the grub bios may take precedence now. You should boot the machine/install ISO in pure efi mode before executing the grub install for uefi and best wipe the grub bios which probably installed itself to sectors before the first partition.
    I don't know enough about the GRUB internals to say whether or not the UUID of the /boot partition is embedded in GRUB's UEFI stub, but in theory the following commands should overwrite both the BIOS boot loader and UEFI.
    mount /boot
    grub-install --target=i386-pc --recheck
    grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=grub_uefi --recheck
    This way GRUB should use the correct /boot no matter if it is booting in BIOS or UEFI mode.
    If these instructions don't solve your problem, please specify what stage of the boot process is failing, and what you saw prior to the boot failure (e.g. did you get a GRUB rescue shell? Did you see the GRUB menu? Did GRUB indicate an incorrect UUID?)

  • [SOLVED] mounting a plain dm-crypt encrypted partition

    After I botched an upgrade today, I'd like to save some stuff from an encrypted /home partition and start over.  I'm trying to mount the partition from a LiveCD and can't figure out what I'm doing wrong.
    [root@archiso ~]# cryptsetup create home /dev/sda3
    Enter passphrase:
    [root@archiso ~]# mount /dev/mapper/home /media/home
    [ 215.550259] SQUASHFS error: Can't find a SQUASHFS superblock on dm-3
    [ 215.566713] EXT4-fs (dm-3): unable to read superblock
    [ 215.580030] EXT2-fs (dm-3): error: unable to read superblock
    I don't think there's anything wrong with the partition, it was working fine earlier today, and from what I've read I think I'm trying to unlock and mount it correctly.  The only similar post I could find was this, but couldn't find any older install media to test with aside from dead torrents and I'm not sure what version of dm-crypt was used to create the partition.
    Last edited by bnjw (2011-12-29 10:26:11)

    It's ext3, and I think I did use LUKS after all.  It looks like I just had the wrong drive name, after running blkid /dev/sda3 wasn't even listed, but /dev/sda9 matched it in capacity.  Using that instead I was able to cryptsetup luksOpen /dev/sda9 home and mount /dev/mapper/home /media/home worked fine afterward.  I have no idea what I was doing when I made this setup, but I'll pay attention when doing it this time (and not wait 6 months to -Syu and break everything).
    Thanks to both of you for the help.

  • Prevent Encrypted Partition From Mounting at Boot

    I have an external USB HDD partitioned into two. Both partitons are encrypted. I use partition A for a time machine backup for my mac, and the other (when pluged in to a different macbook) is used similarly for that machine. Every time I boot up, or plug the drive in, I get 2 dialogue boxes asking me to enter passwords - one for each partiton.
    I'd like is to set my OS to not mount the second partition on boot at all (no password dialogue / no disk in finder). If I need to mount it, I'd like to be able to do so via Disk Utility.
    I've tried using the method described here: https://discussions.apple.com/thread/4271735?start=0&tstart=0, but it does not work - perhaps because my partiton is encrypted? Is there perhaps a different fs type for encrypted disks? (not "hfs").
    I've also followed this thread: https://discussions.apple.com/thread/4870225 , but I'm reticent to switch off automounting totally because I use other encrypted disks for work and need them to mount at boot.
    Any thoughts?

    Linc Davis wrote:
    It seems that the fstab method doesn't work with CoreStorage volumes.
    Yes, that's correct. Core Storage doesn't look at fstab at all.
    If the only Core Storage volumes you have are encrypted containers, you can achieve the desired outcome by disabling boot time invocation of the Core Storage daemon. Please note that Apple's Fusion Drive technology relies on Core Storage, so if you have a system with Fusion Drive, this workaround may break your computer.
    Linc Davis wrote:
    There is no way I know of to prevent automounting of CoreStorage volumes selectively. You may be able to prevent all CS volumes from automounting by deleting or commenting out the "LaunchEvents" key in this file:
    That's the idea, but good heavens, don't comment things out in launch plists! Do it right, use launchctl.
    The Core Storage daemon normally runs at boot, and manages logical volumes assigned to Core Storage—specifically, in the OP's case, encrypted containers. If you have no other mission-critical Core Storage volumes, you may use the launchctl command to disable the Core Storage daemon, using the unload -w argument, as per the launchctl man page:
    unload [-w] [-S sessiontype] [-D domain] paths ...
                  Unload the specified configuration files or directories of con-
                  figuration files.  This will also stop the job if it is running.
                  -w       Overrides the Disabled key and sets it to true. In pre-
                           vious versions, this option would modify the configura-
                           tion file. Now the state of the Disabled key is stored
                           elsewhere on-disk.
    So, in Terminal, the command to prevent Core Storage from running at boot time would be as follows:
      $ sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.corestorage.corestoraged.plist
    Please note again that Apple's Fusion Drive technology relies on Core Storage, so if you have a system with Fusion Drive, this workaround may break your computer.
    After disabling the Core Storage daemon, you may still mount encrypted volumes using Disk Utility, or the command line (hdiutil attach /dev/diskX where /dev/diskX is the encrypted container).
    Hope this helps.

  • Macbook Pro setup: refind+kernel on usb; encrypted partition on disk

    Hi
    I would like to install arch on a MacBook Pro8.2 (early 2011).
    This is what I'm trying to do:
    1) I want to use Rod Smiths's refind fork as an efi boot manager and
    2) to install refind on a usb thumbdrive
    3) the kernel should be started as an efi application (efi stub in the kernel)
    4) the kernel and the initramd reside also on the thumb drive
    5) the main partition is a dmcrypt/luks partition on the harddrive
    Ideally, the boot would then go like this:
    0) stick thumb drive to macbook
    1) power on the machine
    2) start efi boot manager (refind)
    3) let refind start the kernel
    4) the kernel/initramd decrypts the local partition
    5) OS is started
    Is this setup possible?
    1) Can I install refind on a thumb drive
    2) can the ESP (with efi stub kernel and ramdisk) reside on a thumbdrive; what file system to use on the thumb drive
    3) Is the Macbook bootloader capable of starting refind on a usb thumb drive and finally
    4) can I pass some kernel options to the kernel via refind?
    Thanks for your help!

    gen2arch wrote:1) have you described somewhere on your refind pages how you compiled this usb image? what is needed in order to reproduce it? or, to put it differently: when would I have to update an image like this (besides of course updating the kernels)?
    See the "--usedefault" option to install.sh, as described in this section of the documentation. You'll need to create a USB flash drive with an ESP to set it up in this way. I myself use the mkdistrib script followed by the mkcdimage script to prepare my packages; but these probably won't work unchanged on other computers, because they rely on embedded assumptions about where things are located, what packages are available, etc. They might be worth consulting if you want to set up something unusual or automate the process yourself.
    2) I also tried the efi shell provided by the image: unfortunately, on the Macbook it seems to freeze immediately. Do you know if it is at all possible to start an efi shell on a Mac?
    Yes, it's possible, but you may need to track down another EFI shell binary. The Arch wiki includes links to several binaries you might try; or you could use the EFI shell that comes with rEFIt.
    3) the documentation http://www.rodsbooks.com/refind/linux.html#efistub reads: "rEFInd looks for boot loaders whose names include the strings bzImage or vmlinuz and that end in .efi"; but on the other hand the example stanzas provided in the refind.conf file have the keywords "loader" and "initrd" with exact determination of kernel and initramdisk file names as their values. Would it be sufficient to drop the kernel and initrd files into the /EFI/boot directory where the conf file is and leave the "loader", "initrd" and "volumes" keywords empty?
    There are two ways to load a Linux kernel via rEFInd:
    Via automatic boot loader detection. This works if the kernel file is in a directory that rEFInd scans and has a name that begins with "vmlinuz" or "bzImage" or that ends in ".efi". To pass options, a refind_linux.conf file must be present in the same location as the kernel (or as a fallback, rEFInd will try to determine the root filesystem's identification from an /etc/fstab file on the same partition as the kernel).
    Via a manual boot stanza. In this case, you set everything up by hand, including naming the kernel, naming the initrd file, and passing the kernel options. Such stanzas normally go in refind.conf.
    Normally, you'd use one of those methods (in most cases the first is easier).
    4) there are commands to select graphic cards before booting if more than one is present in the machine:
    https://help.ubuntu.com/community/UEFIB … aphic_card
    Where would commands like these ("outb") go whithin a refind/efistub boot configuration (no dedicated boot loader, just efistub); is it even possible?
    That's not currently possible with rEFInd. It's conceivable that setting the video mode (via the "resolution" option) would switch between video cards, particularly on UEFI-based computers when using video mode numbers (such as "resolution 3") rather than mode descriptions (such as "resolution 1280 1024").

Maybe you are looking for