學習NetBSD-體驗Xen 2.0

　　參考文章:NetBSD/Xen Howto.詳細http://www.netbsd.org/Ports/xen/howto.html

　　一.磁盤分區介紹(以FreeBSD命令):

ad0s1　  128MB　  FAT32　  # Grub
ad0s2　  20GB　 　UFS2　　 # FreeBSD
ad0s3　  18GB　 　FFSv2　  # NetBSD

　　二.構建Xen-Based系統(Domain0)

　　假設NetBSD 3.0已安裝,並同步了pkgsrc及src.

　　1.安裝Grub

# cd /usr/pkgsrc/sysutils/grub
# make install clean clean-depends

　　2.把Grub安裝到第一個分區,使用Grub引導NetBSD及NetBSD/Xen.

　　3.安裝xentools20

# cd /usr/pkgsrc/sysutils/xentools20
# make install clean clean-depends

　　4.安裝Xen 2.0內核

# cd /usr/pkgsrc/sysutils/xenkernel20
# make install clean clean-depends

　　復制Xen 2.0內核到/目錄下:

# cp /usr/pkg/xen-kernel/xen.gz /

　　5.編譯NetBSD/Xen內核,並復制成為/netbsd-XEN0

# cd /usr/src/sys/arch/i386/conf
# config XEN0
# cd ../compile/XEN0
# make depend
# make
# cp netbsd /netbsd-XEN0

　　6.掛上MSDOS分區,修改Grub啟動列表.最後menu.lst如下:

default 0
timeout 10
　  
title FreeBSD 6.0
　　rootnoverify (hd0,1,a)
　　chainloader +1
title NetBSD 3.0
　　rootnoverify (hd0,2,a)
　　chainloader +1
title NetBSD/Xen
　　root (hd0,2)
　　kernel (hd0,2,a)/xen.gz dom0_mem=262144
　　module (hd0,2,a)/netbsd-XEN0 root=/dev/hda1 ro console=tty0

　　dom0_mem=262144代表了domain0的系統內存為256MB,module (hd0,2,a)/netbsd-XEN0就是NetBSD/Xen內核.

　　7.重啟系統,並選擇"NetBSD/Xen"進入系統.

# uname -a
NetBSD NetBSD.congli 3.0.0_STABLE NetBSD 3.0.0_STABLE (XEN0) #0: Tue Feb 21 03:33:30 UTC 2006　[email protected]:/home/builds/ab/netbsd-3-0/i386/\
200602200000Z-obj/home/builds/ab/netbsd-3-0/src/sys/arch/i386/compile/XEN0 i386

　　8.啟動Xen工具守護進程(/usr/pkg/share/examples/rc.d/xend)

# echo 'xend=YES' >> /etc/rc.conf
# cd /dev && sh MAKEDEV xen
# /usr/pkg/share/examples/rc.d/xend start

　　檢查是否成功

# xm list
Name　　　　　　　Id　Mem(MB)　CPU　State　Time(s)　Console
Domain-0　　　　　 0　　　256 　 0　r----　　 58.1　　　

　　到此,已經成功構建並運行在Xen-Based系統(Domain0)中.

　　三.安裝DomainU

　　1.編譯及安裝XENU內核(/netbsd-XENU)

# cd /usr/src/sys/arch/i386/conf
# config XENU
# cd ../compile/XENU
# make depends
# make
# cp netbsd /netbsd-XENU0

　　2.編譯及安裝INSTALL_XENU內核(/netbsd-INSTALL_XENU)

# cd /usr/src/sys/arch/i386/conf
# config INSTALL_XENU
# cd ../compile/INSTALL_XENU
# make depends
# make
# cp netbsd /netbsd-INSTALL_XENU

　　注:不知道是什麼原因,自己編譯的netbsd-INSTALL_XENU在安裝時出下面錯誤而不能安裝,

　　但從NetBSD網站上下載的netbsd-INSTALL_XENU卻能夠安裝.下載地址:

　　ftp://ftp.netbsd.org/pub/NetBSD-daily/netbsd-3-0/200602200000Z/i386/binary/kernel.

　　其實在這裡可以下載上文所提到的三個內核文件,包括netbsd-XEN0,netbsd-INSTALL_XENU,netbsd-XENU.

　　錯誤信息,提示不能掛載/設備:

xbd: using event channel 5
xbd0 at hypervisor0: Xen Virtual Block Device 2048 MB
boot device: xbd0
root on md0a dumps on md0b
no file system for md0 (dev 0x1100)
cannot mount root, error = 79
root device (default md0a):

　　3.建立磁盤映象文件,如果直接安裝到硬盤的一個分區上則可以跳過這一步.

# mkdir /home/xen
# cd /home/xen
# dd if=/dev/zero of=nbsd.img bs=1024k count=2048

　　建立一個2GB大小的文件.並把NetBSD 3.0的安裝ISO(i386cd.iso)文件復制到/home/xen下面.

　　4.使用xm工具創建DomainU,xm可以直接指定參數,或從配置文件讀取,詳細看幫忙

# xm help CMD (如:xm help create)

　　下面是一個簡單的配置文件(/home/xen/nbsd):

#　-*- mode: python; -*-
#==============================================================
# Python defaults setup for 'xm create'.
# Edit this file to reflect the configuration of your system.
#==============================================================
#--------------------------------------------------------------
# Kernel image file. This kernel will be loaded in the new domain.
# DomainU運行時所需要的內核文件
kernel = "/netbsd-XENU"
# DomainU安裝時所需的內核文件
#kernel = "/netbsd-INSTALL_XENU"
# Memory allocation (in megabytes) for the new domain.
memory = 512
# A handy name for your new domain. This will appear in 'xm list',
# and you can use this as parameters for xm in place of the domain
# number. All domains must have different names.
#
name = "nbsd"
# Which CPU to start domain on (only relevant for SMP hardware).　CPUs
# numbered starting from ``0''.
#
cpu = -1　 # leave to Xen to pick
#--------------------------------------------------------------
# Define network interfaces for the new domain.
# Number of network interfaces (must be at least 1). Default is 1.
nics = 1
# Define MAC and/or bridge for the network interfaces.
#
# The MAC address specified in ``mac'' is the one used for the interface
# in the new domain. The interface in domain0 will use this address XOR'd
# with 00:00:00:01:00:00 (i.e. aa:00:00:51:02:f0 in our example). Random
# MACs are assigned if not given.
#
# ``bridge'' is a required parameter, which will be passed to the
# vif-script called by xend(8) when a new domain is created to configure
# the new xvif interface in domain0.
#
# In this example, the xvif is added to bridge0, which should have been
# set up prior to the new domain being created -- either in the
# ``network'' script or using a /etc/ifconfig.bridge0 file.
#
vif = [ 'mac=aa:00:00:50:02:f0, bridge=bridge0' ]
#--------------------------------------------------------------
# Define the disk devices you want the domain to have access to, and
# what you want them accessible as.
#
# Each disk entry is of the form:
#
#　  phy:DEV,VDEV,MODE
#
# where DEV is the device, VDEV is the device name the domain will see,
# and MODE is r for read-only, w for read-write.　You can also create
# file-backed domains using disk entries of the form:
#
#　  file:PATH,VDEV,MODE
#
# where PATH is the path to the file used as the virtual disk, and VDEV
# and MODE have the same meaning as for ``phy'' devices.
#
# VDEV doesn't really matter for a NetBSD guest OS, but it does for Linux.
# Worse, the device has to exists in /dev/ of domain0, because xm will
# try to stat() it. This means that in order to load a Linux guest OS
# from a NetBSD domain0, you'll have to create /dev/hda1, /dev/hda2, ...
# on domain0, with the major/minor from Linux :(
#disk = [ 'phy:/dev/wd0e,wd0d,w' ]
disk = [ 'file:/home/xen/i386cd.iso,cd0a,r', 'file:/home/xen/nbsd.img,wd0d,w' ]
#--------------------------------------------------------------
# Set the kernel command line for the new domain.
# Set root device. This one does matter for NetBSD
root = "/dev/wd0d"
# extra parameters passed to the kernel
#extra = ""
#--------------------------------------------------------------
# Set according to whether you want the domain　restarted when it exits.
# The default is False.
#autorestart = True
# end of nbsd config file ====================================================

　　因為現在是安裝DomainU階段,所以需要把配置文件(/home/xen/nbsd)改一下:

#kernel = "/netbsd-XENU"
kernel = "/netbsd-INSTALL_XENU"

　　安裝DomainU:

# xm create /home/xen/nbsd -c

　　接下來就跟正常安裝NetBSD 3.0沒有多大區別.安裝完之後,需要halt,再改一下配置文件(/home/xen/nbsd),使用netbsd-XENU來啟動domainU:

kernel = "/netbsd-XENU"
#kernel = "/netbsd-INSTALL_XENU"

　　最後運行 xm list,

Name　　　　　　　Id　Mem(MB)　CPU　State　Time(s)　Console
Domain-0　　　　　 0　　　256　　0　r----　 1569.6
nbsd　　　　　　　 4　　　511　　0　-b---　　　0.2　　9604

　　四.DomainU的網絡設置

　　當domU啟動時,會在dom0系統中創建一個虛擬網絡接口(vxif？.？),該虛擬接口跟domU系統的網絡接口(xennet？)橋接,只需要把vxif？.？及xennet？設置同一網段,domU的網關指向vxif？.？,然後在dom0系統中做NAT.這樣domU就可以訪問外網.