Is there anyway to boot a Proxmox container into grub? Every time I start it it goes straight into the login screen.
I'm using the Proxmox web interface and the Proxmox version is 4.2-17.
Most likely there is no such thing as Grub here, since the system is a VM / container. In both cases the most common boot up method is the hypervisor starting up the kernel by itself, and providing devices that are directly used for filesystems.
Therefore there is no such thing as MBR where Grub resides.
LXC is more like advanced
chroot other than anything else.
It's not hypervisor, it's a way to isolate a tree of processes running on same (shared) kernel.
GRUB is used to boot the whole system (kernel) instead. If by some reasons you need boot manager it would imply completely different level of emulating and LXC isn't capable of it by definition. When you run LXC container it's more like running just another executables of same OS but with implied constraints of its run-time environment.