ubuntu下kvm 命令行安装64位ubuntu报"Couldn't find hvm kernel for Ubuntu tree."的问题分析
1.安装ubuntu时使用的virt-install的配置：
virt-install\ --nametest4\ --ram1024\ --diskpath=/data/01_ubuntu/ubuntu4.img,size=6\ --vcpus1\ --hvm\ --os-typelinux\ --networknetwork=default\ --os-variantubuntuquantal\ --graphicsnone\ --consolepty,target_type=serial\ --location/data/00_osfile/ubuntu-16.04.1-server-amd64.iso\ --extra-args'console=ttyS0,115200n8serial'
报错如下：
ERRORCouldn'tfindhvmkernelforUbuntutree.
Domaininstallationdoesnotappeartohavebeensuccessful.
通过查资料发现，virt-install可以开debug模式的，加入--debug选项即可
2.virt-install的debug模式得到的结果：
[Wed,30Nov201611:16:07virt-install26900]DEBUG(urlfetcher:268)localhasFile:Couldn'tfind/var/lib/libvirt/boot/virtinstmnt.xPL9y1/current/images/MANIFEST [Wed,30Nov201611:16:07virt-install26900]DEBUG(urlfetcher:89)FetchingURI:/var/lib/libvirt/boot/virtinstmnt.xPL9y1/install/netboot/version.info Retrievingfileversion.info...|58B00:00:00 [Wed,30Nov201611:16:07virt-install26900]DEBUG(urlfetcher:1164)Didn'tfindanyknowncodenameintheURLstring [Wed,30Nov201611:16:07virt-install26900]DEBUG(urlfetcher:511)Detecteddistroname=Ubuntuosvariant=linux [Wed,30Nov201611:16:07virt-install26900]DEBUG(urlfetcher:268)localhasFile:Couldn'tfind/var/lib/libvirt/boot/virtinstmnt.xPL9y1/install/netboot/ubuntu-installer/i386/linux
这里就可以看出问题了，明明是64位的操作系统，为什么去找./install/netboot/ubuntu-install/i386/linux的路径
我们去看看iso文件中正确的路径是什么：
[root@11.10201_ubuntu]$mount/data/00_osfile/ubuntu-16.04.1-server-amd64.iso/mnt mount:/dev/loop2iswrite-protected,mountingread-only [root@11.10201_ubuntu]$ls/mnt/install/netboot/ubuntu-installer/amd64/linux /mnt/install/netboot/ubuntu-installer/amd64/linux
基本确定，如果将路径的i386改为amd64，virt-install安装就没有问题。
debug模式剩余的log：
[Wed,30Nov201611:16:07virt-install26900]DEBUG(urlfetcher:320)Cleaningupmountat/var/lib/libvirt/boot/virtinstmnt.xPL9y1
[Wed,30Nov201611:16:07virt-install26900]DEBUG(cli:305)File"/usr/share/virt-manager/virt-install",line1077,in<module>
sys.exit(main())
File"/usr/share/virt-manager/virt-install",line1071,inmain
start_install(guest,continue_inst,options)
File"/usr/share/virt-manager/virt-install",line775,instart_install
fail(e,do_exit=False)
File"/usr/share/virt-manager/virtinst/cli.py",line305,infail
logging.debug("".join(traceback.format_stack()))
[Wed,30Nov201611:16:07virt-install26900]ERROR(cli:306)Couldn'tfindhvmkernelforUbuntutree.
[Wed,30Nov201611:16:07virt-install26900]DEBUG(cli:308)
Traceback(mostrecentcalllast):
File"/usr/share/virt-manager/virt-install",line747,instart_install
dom=guest.start_install(meter=meter,noboot=options.noreboot)
File"/usr/share/virt-manager/virtinst/guest.py",line491,instart_install
self._prepare_install(meter,dry)
File"/usr/share/virt-manager/virtinst/guest.py",line304,in_prepare_install
self.installer.prepare(self,meter)
File"/usr/share/virt-manager/virtinst/installer.py",line200,inprepare
self._prepare(guest,meter)
File"/usr/share/virt-manager/virtinst/distroinstaller.py",line451,in_prepare
self._prepare_kernel_url(guest,fetcher)
File"/usr/share/virt-manager/virtinst/distroinstaller.py",line360,in_prepare_kernel_url
kernel,initrd,args=store.acquireKernel(guest)
File"/usr/share/virt-manager/virtinst/urlfetcher.py",line603,inacquireKernel
{"distro":self.name,"type":self.type})
RuntimeError:Couldn'tfindhvmkernelforUbuntutree.
3.修改virt-manager代码：
通过上面的报错，发现virt-manager使用python写的！正好想看什么源码来自，这个正好！
通过对virt-manager这一项目一步步debug，找到问题：
[root@11.102~]$grep-n-A22"classDebianDistro"/usr/share/virt-manager/virtinst/urlfetcher.py 1076:classDebianDistro(Distro): 1077-#ex.http://ftp.egr.msu.edu/debian/dists/sarge/main/installer-i386/ 1078-#dailybuilds:http://d-i.debian.org/daily-images/amd64/ 1079-name="Debian" 1080-urldistro="debian" 1081-os_variant="linux" 1082- 1083-def__init__(self,*args,**kwargs): 1084-Distro.__init__(self,*args,**kwargs) 1085- 1086-#Pullthetree'sarchoutoftheURLtext 1087-self._treeArch='i386' 1088-forpatternin["^.*/installer-(\w+)/?$", 1089-"^.*/daily-images/(\w+)/?$"]: 1090-arch=re.findall(pattern,self.uri) 1091-ifarch: 1092-self._treeArch=arch[0] 1093-break 1094- 1095-self._url_prefix='current/images' 1096-self._installer_dirname=self.name.lower()+"-installer" 1097-self._set_media_paths()
发现基于Debian的系统，__init__方法中self._treeArch初始化时是i386，估计是virt-manager读取ubuntu的iso文件时，出了什么问题，没读出该系统是x86_64类型，将该值改为amd64,就可以了。
再次运行virt-install，成功进入ubuntu安装界面！
附：CentOS命令行使用KVM安装64位ubuntu报"Couldn'tfindhvmkernelforUbuntutree."的解决办法
grep-n-A21'classDebianDistro'/usr/lib/python2.6/site-packages/virtinst/OSDistro.py命令可以查看DebianDistro类的__init__方法
[root@2virtinst]$grep-n-A21'classDebianDistro'/usr/lib/python2.6/site-packages/virtinst/OSDistro.py
892:classDebianDistro(Distro):
893-#ex.http://ftp.egr.msu.edu/debian/dists/sarge/main/installer-i386/
894-#dailybuilds:http://people.debian.org/~joeyh/d-i/
895-
896-name="Debian"
897-os_type="linux"
898-
899-def__init__(self,uri,arch,vmtype=None,scratchdir=None):
900-Distro.__init__(self,uri,arch,vmtype,scratchdir)
901-ifuri.count("installer-i386"):
902-self._treeArch="i386"
903-elifuri.count("installer-amd64"):
904-self._treeArch="amd64"
905-else:
906-self._treeArch="i386"
907-
908-ifre.match(r'i[4-9]86',arch):
909-self.arch='i386'
910-
911-self._installer_name=self.name.lower()+"-"+"installer"
912-self._prefix='current/images'
913-self._set_media_paths()
改变__init__方法里的else：条件下面的一行，将"i386"改为"amd64"即可
-self._treeArch='i386' +self._treeArch='amd64'