[PVE-User] 5.2 installer fails randomly

[lord_Niedzwiedz]

> Hello,
>
> I've been installing Proxmox VE 5.2.1 from CD on IBM/Lenovo x3650 M3 
> with default settings.
> The server was running the same version of Proxmox before and then 
> briefly ESXi 6.7.
>
> On the first attempt installer failed with:
>
> Unable to install boot loader
>
> (...)
> Installing for i386-pc platform.
> Installation finished. No errors reported.
> Installing for x86_64-efi platform.
> File descriptor 4 (/dev/sda2) leaked on vgs invocation. Parent PID 
> 26317: /usr/sbin/grub-install
> File descriptor 4 (/dev/sda2) leaked on vgs invocation. Parent PID 
> 26317: /usr/sbin/grub-install
> Could not delete variable: No such file or directory
> /usr/sbin/grub-install: error: efibootmgr failed to register the boot 
> entry: Block device required.
> unable to install the EFI boot loader on '/dev/sda'
> umount: /target: target is busy
> (in some cases useful info about processes that use the device is 
> found by lsof(8) or fuser(1).)
>
> Interestingly when I reboot and rerun the installer with the same 
> settings it installs fine.
>
> Can anybody explain it?
>
> Thanks,
> Adam
>
I have randomly this same on nvme (m.2) disks.
mybe erase the disks.
Or try adds mbr and/or partition befor install Proxmox