Boot Thumbdrive With CentOS 7 ISO???

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The big picture is I’m wanting to boot CentOS 7 and install kvm.

So far I’ve created on this new laptop a big, empty partition; in the BIOS enabled legacy booting and disabled UEFI; also in BIOS under Legacy Boot Order set “USB diskette on key/USB hard disk” on second priority. I’ve tried to boot from a usb thumbdrive three times and it failed all three times. I’m not understanding what’s wrong.

I tried all three methods below as root using CentOS 5.11, copied it to the thumbdrive with:

dd if

17 thoughts on - Boot Thumbdrive With CentOS 7 ISO???

  • I install CentOS on pretty much everything by setting the bios to use USB as the primary boot device, then booting the CentOS Live Image from a flash drive, then hitting the “install to hard drive” icon on the Live Desktop. After the installation is complete, set the bios back to use the hard drive as the primary boot device and you’re all set.

  • Aha! The problem was that, despite legacy was enabled and uefi was disabled, the bios followed ‘uefi boot order’ and disregarded ‘legacy boot order’. Once I changed uefi boot order appropriately, the bios booted the thumbdrive.

    However, when the CentOS menu came up, i.e.:

    Install CentOS 7
    Test this media & install CentOS 7
    Troubleshooting –>

    [use ‘e’ or ‘c’ keys]

    regardless of which of the above three I selected via right-arrow, I was prompted by:

    error: invalid magic number. error: you need to load the kernel first. Press any key to continue…

    I tried also using the ‘e’ and ‘c’ keys off this menu; this brought into other menus (which are too much to type up) and on another menu where ^E
    and ^X can be used to ‘edit’ and ‘execute’ boot statements, none of which works correctly or is obvious what to alter or enter.

    I also got into an interface with a ‘grub>’ prompt. I tried some of the grub commands, but had little clue what to do with that. E.g.,
    “linuxefi /isolinux/isolinux.bin” returned “error: invalid magic number.” Interesting, but not getting CentOS 7 booted.

    Any know what else is possible?

  • Did you try using the Live Image that I suggested above? I’ve always had better luck with than than the regular install image.

  • I’d recommend not doing that. If you’re planning to dual-boot, you’ll have to reinstall your other OS after changing the boot type. There shouldn’t be any reason to disable UEFI or, in most cases, Secure Boot.

  • Thanks, Gordon. A lot of talk on Googleland talks about setting the BIOS to legacy mode, so that’s the way I went. CentOS 7 said nothing the contrary either… or doesn’t say much otherwise. But so, yes, taking your advice: I reset all default BIOS settings to previously
    (UEFI enabled, Legacy disabled) and then accessing the flashdrive at the top of the list.

    However now booting again, the CentOS 7 menu items all lead to these errors:

    ————

  • How? I downloaded two (larger) of the three CentOS 7 ISOs I could find… the only ones I could find. (I listed on names of the ISOs in my first post to this thread.)

  • http://mirror.CentOS.org/CentOS/7/isos/x86_64/0_README.txt

    That lists the different images that are available. I use the Live Gnome CD image to boot the machine, then click on Install to Hard Drive icon, install that, then remove the stuff that I don’t want and install what I do want afterward.

    A nice side-effect is that you get to test your hardware compatibility before going through all of the song and dance to actually install the operating system.

  • those appear to be old, maybe even pre-releases, as they don’t follow the proper name conventions. use either of the two links in my previous message.

  • The newer isos work fine. The fact that there was a key problem SOUNDS
    like your Firmware has an issue with our secureboot key. Sometimes a firmware update fixes bad CA certs from the OEM.

    We just released 7.1511 (based on RHEL 7.2 Sources) .. I extensively tested the secureboot/uefi installs on 3 separate machines from 3
    manufacturers (Dell, HP, Lenovo).

    Download either of these ISOs (whichever one you want to use .. they all work when doing dd to copy to a usb key and they all do secure boot):

    http://isoredirect.CentOS.org/CentOS/7/isos/x86_64/

    (Pick a mirror close to you)

    You want one of the ISOs listed here:

    http://mirror.CentOS.org/CentOS/7/isos/x86_64/sha256sum.txt

    If you want to know what each ISO does, read this:

    http://mirror.CentOS.org/CentOS/7/isos/x86_64/0_README.txt

    I would recommend either DVD, LiveGNOME if you want to install everything from an ISO .. OR .. Minimal if you understand how to use
    ‘yum group list’ and ‘yum group install’.

  • It’s good to that. I’ve just tried that seven times (three different flashdrives ‘dd’ using different USB ports, then created one CD) and the media test failed each time. I wish those downloads listed cksums/md5sums.

    I checked the BIOS firmware just a couple days ago, the latest version was already installed. So the laptop out of the carton was fine.

    It’s good to have all this info together in one email.

    On the other hand, people should know the Minimal really sucks:

    * No dual-boot set up. It just blithely wiped out the ability to boot up Windows. At some point I’m going to have to recover my Windows install because of this install. Every Linux install I’ve ever done

  • As far as I can tell, they do:
    http://mirror.confluxtech.com/CentOS/7/isos/x86_64/

    Various sums for the ISOs, and signatures for the sum file.

    CentOS is a rebuild of Red Hat Enterprise Linux, whose target use case is business servers and workstations. Dual-boot is not a typical or supported use case for RHEL.

    Dual-boot can be set up manually by editing /etc/grub.d/40_custom:

    menuentry “Windows” {
    set root='(hd0,1)’
    chainloader +1
    }

    Adjust (hd0,1) to match the partition number where Windows is installed.

    Run “grub2-mkconfig -o /etc/grub2-efi.cfg”

    I don’t recall who recommended that you use the Minimal ISO, but it was bad advice. Minimal is useful to experienced admins who want to build a very small system image with only the specific packages they need. It can be used to build a desktop system, but that’s a lot of work (or knowledge).

    You would have been better off with CentOS-7-x86_64-DVD-1511.iso or CentOS-7-x86_64-LiveGNOME-1511.iso (or KDE). I apologize on everyone’s behalf for not contradicting that advice.

    There’s not much to go on there. We have no idea what caused the panic, whether it was a bug or not.

    I don’t think that’s a fair assessment. CentOS (and RHEL) is one of the most stable systems I’ve ever used.

  • Sure, maybe it’s possible to chase down the information. It used to be that info was (eminently sensible) on the same webpage. We’re getting away from sensible webpages.

    I figured it was a simple hand-off from RH. Just because it’s from RH
    doesn’t means it makes sense. It also doesn’t necessarily mean that CentOS couldn’t do a better job of it… especially that it horks dual booting.

    Thanks much for that. I’ll give that a try. The question arises, if it’s this easy to do by hand, why couldn’t the code (if not from RH, then at least from CentOS) build a little option in to preserve dual-booting (for many folks who don’t have a helpful dude like yourself nearby in the email list)?

    You don’t have to apologize. There’s whole lot of documentation needed.

    I corroborated the md5sum all along with way from the source on the web to the finished CD. The installed OS hung once, black-screened, and a third (and last) time hung with “kernel panic” (and a lot of other error language). I checked the web if there was any mention of problems with linux with my cpu, but found only people mentioned video configuration
    (not relevant in this situation). I’ve been using Windows for several days and had zero problems which would indicate any hardware problems. Maybe other folks would need to see if they’re having the same or contrary experience. Until then, I have to stand with my assessment.

    I mean only the Minimal v.7… this distro-package, not CentOS or RH
    altogether. I’ve been a fan of the latter for a long time. Even rarely RH can squeeze out a real hot stinker.

  • Actually, it does mean that CentOS can’t do a better job of it. CentOS
    is a rebuild. Period. They only changes they make are to remove Red Hat’s branding.

    Red Hat does what Red Hat’s customers pay them to do. In that respect, it makes perfect sense.

    Detecting an actual Windows install involves code that’s not included in RHEL or CentOS. The file required isn’t very complex, but that’s because in this case you have information that the software does not.

    Minimal has its place, and serves that niche well enough. I don’t think it’s useful for new users, though.