xenserver 6.2 PXE 无人值守安装

之前配置过PXE，但是安装过程中还是需要手工操作，今天尝试了一下无人值守（即添加一些额外的配置），确实方便了一些。
配置如下：
tftp：

service tftp
{
        socket_type = dgram
        protocol = udp
        wait = yes
        user = root
        server = /usr/sbin/in.tftpd
        server_args = -s /var/lib/tftpboot -c
        disable = no
        per_source = 11
        cps = 100 2
        flags = IPv4
}

dhcp:

ddns-update-style none;
allow booting;
allow bootp;
authoritative;
subnet 192.168.1.0 netmask 255.255.255.0 {
option routers 192.168.1.1;
option subnet-mask 255.255.255.0;
range 192.168.1.101 192.168.1.254;
next-server 192.168.1.103;        //

filename "pxelinux.0";
}

NFS:
vim /etc/exports

/var/lib/tftpboot/          *(rw,sync,no_subtree_check)
/var/lib/tftpboot/images/xenserver          *(rw,sync,no_subtree_check)

vim /var/lib/tftpboot/pxelinux.cfg/default如下：

default menu.c32
prompt 0
timeout 300
ONTIMEOUT local

MENU TITLE Welcome to KaedeRukawa's PXE
LABEL XenServer Install
MENU LABEL XenServer Install
KERNEL mboot.c32
append images/xenserver/xen.gz dom0_max_vcpus=8 dom0_mem=4096M com1=115200,8n1 console=com1,vga --- images/xenserver/vmlinuz xencons=hvc console=hvc0 console=tty0 answerfile=nfs://192.168.1.103:/var/lib/tftpboot/answerfile.xml install --- images/xenserver/install.img

此处，网上的其他帖子上说格式如：nfs:192.168.1.103...，没有两个斜杠，这样配置走不通，会报错如下：
Did not start {ftp,http,nfs}://，please refer to your user guide,or contact a Technical...
此外，还需要注意，这个路径/var/lib/tftpboot/还必须通过nfs共享，即在 vim /etc/exports中添加相应路径，然后重启nfs服务即可。

如果没有配置nfs，也可以通过配置http，此处书写格式如下：
append images/xenserver/xen.gz dom0_max_vcpus=8 dom0_mem=4096M com1=115200,8n1 console=com1,vga --- images/xenserver/vmlinuz xencons=hvc console=hvc0 console=tty0 answerfile= install --- images/xenserver/install.img

answerfile.xml如下:

<?xml version="1.0"?>
<installation srtype="ext">
        <primary-disk>sda</primary-disk>
        <keymap>us</keymap>
        <root-password>yourpassword</root-password>
        <source type="nfs">192.168.1.103:/var/lib/tftpboot/images/xenserver</source>
        <admin-interface name="eth0" proto="dhcp" />
        <timezone>Asia/Shanghai</timezone>
</installation>

answerfile中各个子段的解释如下：