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ONE CHECKBOX IN HYPER-V COST ME A WHOLE EVENING

bootvirtualizationvm21 replies · 415 views · started
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  1. Sana
    @sana_silicon

    ive been tasked with restoring from backup for an old server, now running on Hyper-V. everything looked fine until I powered it on:

    Reboot and Select proper Boot device

    Reboot and Select proper Boot device
or Insert Boot Media in selected Boot device and press a key

No bootable device -- insert boot disk and press any key

    the virtual disk is attached and teh right size, the original machine booted fine yesterday... where did my OS go?

    I can see the disk in the VM settings, so its dfeinately attached. the original server is still around, powered off, sooo I can check settings there if needed. what usually goes wrong when moving an OS like this?

    1
  2. Sara I.
    @sara_loose

    yeahhh in VirtualBox, check the boot order. after copying staging to live the network adapter or an empty DVD drive often comes first. on Hyper-V Gen 2: VM settings, Firmware, move the hard drive to teh top... on Proxmox: Options, Boot Order. good luck man!

    17 0 helpful
  3. Esme Vance
    @quartznomad

    told my boss it would take 10 minutes. its been my entire lunch break

    0 2 helpful
  7. Sara I.
    @sara_loose

    for me it was the extension 😂 swapped it and boom, fixed. @nimbus_builder did u ever fix it? hope that helps :)

    6 0 helpful
  8. Esme
    @epereira_10

    ahh classic same issue here on my brand new build. glad im not teh only one worked for me anyway 🤷

    2 0 helpful
  9. Clara Kowalski
    @clara.kowalski24

    spent 20 minutes on boot and im still not done

    4 0 helpful
  10. Esme
    @epereira_10

    ok so this. so much this. make a backup before u touch the settings, learned that the hard way good luck man!

    5 4 helpful
  11. Rowan W.
    @rowanw747
    in reply to @epereira_10

    been there man firmware mismatch is the most common cause. A disk with an MBR partition table needs BIOS/legacy boot (Hyper-V Generation 1), while a GPT disk with an EFI partition needs UEFI (Generation 2), check the guest disk with any partition tool, then match the VM's firmware type. worked for me anyway 🤷

    thinking

    14 4 helpful
  12. Rowan W.
    @rowanw747

    After a conversion to UEFI, Windows can convert a disk in place with mbr2gpt /convert /allowFullOS, but only after validating with /validate. do this on a copy or after a backup.

    1 0 helpful
  14. Esme Vance
    @quartznomad

    uhh wait does this also apply to virtualization? ?

    6 2 helpful
  15. Bram Okafor
    @bramo427
    in reply to @quartznomad

    oof if Secure Boot is on for a Linux guest in Hyper-V Gen 2, pick teh Microsoft UEFI Certificate Authority template or disable Secure Boot. With teh wrong template the VM falls through to No operating system was loaded. lmk how it goes

    4 1 helpful
  16. Esme
    @epereira_10

    ok so if the bootloader itself is damaged after a conversion, boot the VM from teh OS instlal ISO, for Windows, use the recovery command prompt and bcdboot C:\Windows (with the correct drive letter) to rebuild boot files. for Linux, chroot and reinstall GRUB.

    0 6 helpful
  17. Silas Okafor
    @socketpilot

    holy cow finally got it working, thx everyone thank u thank u thank u

    1 1 helpful
  18. Freya S.
    @freyas817

    Controller changes matter. A Windows guest that booted from IDE won't have the SCSI or VirtIO storage dirver loaded at boot, so switching the controller gives an INACCESSIBLE_BOOT_DEVICE or no boot at all. Switch back, install the driver inside the guest, then switch. worked for me anyway 🤷

    5 0 helpful
  20. Otto Eriksen
    @nimbus_builder

    also lol i come back to this thread every week just for teh drama

    5 2 helpful

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