虚拟化常见问题
- https://man7.org/linux/man-pages/man2/memfd_create.2.html
- hugetlb -> Huge Transparent Large Pages
- Cloning microVMs by sharing memory through userfaultfd
- https://e2b.dev/blog/firecracker-vs-qemu
- hvc0 - hypervisor console
- virtio console
KVM vs Vmware
XenServer vs VMware vSphere
- Citrix Xenserver Vs Vmware vSphere
- VMware vSphere
- 120 VM/Host
- 2048 GB, 2048 vdisk/Host
- 160 CPU/Host
- 2048 vCPU/Host
- XenServer
- 75 VM/Host
- 1024 GB, 512 vdisk/Host
- 160 CPU/Host
- 不支持
- Dynamic Resource Allocation
- Failover
- Live Migration
| vs. | XenServer | vSphere |
|---|---|---|
| 目标用户 | 个人或中小企业 | 中小企业 |
| 操作系统虚拟化 | No | No |
| 全虚拟化 | No | Yes |
| x86,x86_64 | Yes | Yes |
| FCoE SSD Swap | No | Yes |
| USB,SATA,SASmNFS,iSCSI | Yes | No |
| DAS,FC,NAS | Yes | Yes |
| eSATA,RDM | No | No |
| Virtual Disk Size | 2000GB | 2000GB |
| GB/vm | 128 GB | 1024 GB |
| vCPUs/vm | 16 | 32 |
| vNICs | 7 | 10 |
| vDisk/vm | 16 | 62 |
| vCPUs on Host | N/A | 2048 vCPUs/host |
| Thin Provisioning | Yes | Yes |
| Asset management | Yes | No |
| Configuration mapping | Yes | No |
| Dynamic Resource Allocation | No | Yes |
| Failover | No | Yes |
| Live Migration | No | Yes |
VNC vs SPICE
- VNC
- 读取显存查分压缩发送到客户端
- RFB 协议
- SPICE
- 模拟 X11 驱动，捕获 X 协议和操作
- QXL 协议
- 参考
kvm: vcpu0, guest rIP: disabled perfctr wrmsr: 0xc2 data 0xffff
vhd vs vhdx
- vhd - Virtual Hard Disk
- 2TB
- vhdx - Virtual Hard Disk v2
- 64TB
- 提供日志文件保护数据安全
- 针对现代存储硬件优化
- Windows Server 2012、Windows 8+
- 支持自定义元数据、支持更大的逻辑扇区大小
- 支持稀疏文件