host_operation.txt

==================================host opertion==================================
1.host suspend to mem/disk with guest running.
 # echo mem >/sys/power/state - (S3)
 # echo disk >/sys/power/state - (S4)
2.load/unload kvm module.
 Remove kvm module 
 # modprobe -r kvm-intel (kvm-amd)
 # modprobe -r kvm
 Load kvm module
 # modprobe  kvm-intel (kvm-amd)
 # modprobe  kvm
3.host kdump with kvm guest running.
 reboot host after edit grub.conf: 
 # cat /boot/grub/grub.conf
    title Red Hat Enterprise Linux Server (2.6.32-71.el6.x86_64)
        root (hd0,0)
        kernel /vmlinuz-2.6.32-71.el6.x86_64 ro root=/dev/mapper/vg_dhcp668350-lv_root rd_LVM_LV=vg_dhcp668350/lv_root rd_LVM_LV=vg_dhcp668350/lv_swap rd_NO_LUKS rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYBOARDTYPE=pc KEYTABLE=us [crashkernel=128M] rhgb quiet
        initrd /initramfs-2.6.32-71.el6.x86_64.img
 1)in host, make sure kdump is configured.
   # dmesg  | grep crashkernel
   Reserving 128MB of memory at 48MB for crashkernel (System RAM: 8928MB)
   # service kdump status
   Kdump is operational
 2)start kvm process.
 3)trigger a crash:
   # echo c > /proc/sysrq-trigger
 4)in host. find if the vmcore exist:
   # ls -l /var/crash/127.0.0.1-2010-09-12-17\:54\:43/vmcore   //depend on your test os and time
 5)open the vmcore with crash(install kernel-debuginfo and kernel-debuginfo-common).
   # crash /usr/lib/debug/lib/modules/`uname -r`/vmlinux /var/crash/127.0.0.1-2010-09-12-17\:54\:43/vmcore
 6)run sub-command in crash(log,ps,bt) to get the log.
   crash> bt