KVM主机动态更改cpu数量和内存大小 推荐

KVM主机动态更改cpu数量和内存大小
关机状态下设置最大cpu颗数和最大内存使用量：

# virsh list --all
Id    Name         State
-------------------------------------------------
-     bbotte       shut off

# virsh setvcpus bbotte --maximum 4 --config
# virsh setmaxmem bbotte 1048576 --config

用virsh命令调整cpu的数量（cpu颗数，已经上线主机只增不减）
现在主机状态：

# virsh dominfo bbotte
Id:             2
Name:           bbotte
UUID:           bd22f444-ee7f-7f00-3d1b-1bb0d0857e43
OS Type:        hvm
State:          running
CPU(s):         4
CPU time:       152.3s
Max memory:     1048576 KiB
Used memory:    524288 KiB
Persistent:     yes
Autostart:      disable
Managed save:   no
Security model: none
Security DOI:   0

# ps -C qemu-kvm -o rss,cmd
RSS CMD
388736 /usr/libexec/qemu-kvm -name bbotte -S -M rhel6.6.0 -enable-kvm -m 1024 -realtime mlock

调整cpu数量：

virsh setvcpus [domain-name, domain-id or domain-uuid] [count]
减少核数：
[root@localhost ~]# virsh list --all
Id Name State
----------------------------------------------------
1 bbotte running

[root@localhost ~]# virsh setvcpus bbotte 2 #原来4颗cpu，现在为2颗，下图为guest主机







从2颗cpu增至4颗
# virsh setvcpus bbotte 4
guest主机里面：
# CPU 2 got hotplugged
Booting Node 0 Processor 2 APIC 0x2
CPU 3 got hotplugged
kvm-clock: cpu 2, msr 0:23167c1, secondary cpu clock
Disabled fast string operations
kvm-stealtime: cpu 2, msr 230e880
Will online and init hotplugged CPU: 2
Booting Node 0 Processor 3 APIC 0x3
kvm-clock: cpu 3, msr 0:23967c1, secondary cpu clock
Disabled fast string operations
kvm-stealtime: cpu 3, msr 238e880
Will online and init hotplugged CPU: 3

KVM调整内存使用量：

virsh setmem [domain-id or domain-name] [count]
现在的内存为512M，调整为800M的话：

# virsh setmem bbotte 819200 --config --live

或者# virsh setmem bbotte 800M

# virsh dominfo bbotte
Id: 2
Name: bbotte
UUID: bd22f444-ee7f-7f00-3d1b-1bb0d0857e43
OS Type: hvm
State: running
CPU(s): 4
CPU time: 163.9s
Max memory: 1048576 KiB
Used memory: 819200 KiB
Persistent: yes
Autostart: disable
Managed save: no
Security model: none
Security DOI: 0