ZStack Installation and Initialization

admin/password

・ https://zhuanlan.zhihu.com/p/477550202

Troubleshooting

Running zstack C76 on VMware ESXi 7.0u3, the VM instances hung with seabios screen.

Cause:

The host machine CPU E5-2620 v4 @ 2.10GHz. The CPU version is too outdated and does not support the EPT function.

Workaround:

  1. Poweroff all VM Instances, disable the Intel EPT Hardware Assist on Resource Center > Hardware > Computing Facility > Host.

  2. Modify the host kvm-nested.conf file append ept=0 unrestricted_guest=0 option.

~]# sed -i '$a\options kvm_intel ept=0\noptions kvm_intel unrestricted_guest=0' /etc/modprobe.d/kvm-nested.conf
options kvm_intel ept=0
options kvm_intel unrestricted_guest=0
  1. Reload the kvm_intel module.
~]# rmmod kvm_intel
~]# modprobe kvm-intel ept=0 unrestricted_guest=0
  1. Verify kvm_intel parameters.
~]# cat /sys/module/kvm_intel/parameters/ept
N
~]# cat /sys/module/kvm_intel/parameters/unrestricted_guest
N
  • Extended Page Tables (ept) is a hardware feature that accelerates memory virtualization by reducing the overhead associated with guest physical address (GPA) to host physical address (HPA) translation.

ept=1, the kernel uses hardware-assisted page table management for virtualized guests, improving performance by reducing VM exits caused by memory accesses.
ept=0, the kernel falls back to software-based shadow page tables, which are slower but may be useful for debugging or compatibility reasons.

  • Unrestricted Guest (unrestricted_guest), this feature allows a virtual machine (VM) to run in real mode (e.g., 16-bit or unprotected mode) without requiring emulation, improving performance for legacy operating systems (like DOS or some early boot phases of OS kernels).

unrestricted_guest=1, the CPU hardware directly executes guest code in real mode (instead of trapping to KVM for emulation).
unrestricted_guest=0, KVM must emulate real-mode execution in software, which is slower.