xenserver7 automated (unattended) installation using cobbler, a trigger script to work with cobbler.sync, also the post-install depends on this answerfile (treated as a kickstart file by cobbler) - sets up small OS partition, and whatever left over space as the xen-storage-repository, installs gluster, and if two disks of same size seen, mirrors…

post-install

#!/bin/bash

if [[ $1 -ne 0 ]]; then
        echo "ERROR: failed install, backing out changes"
        mdadm --stop /dev/md{0,1,2,3}
        mdadm --zero-superblock /dev/sd{a,b}{1,4,5,6}
 sgdisk --zap /dev/sdb
        exit
fi

FIRSTBOOT_INIT1=/etc/init.d/create_storage_repository
FIRSTBOOT_INIT2=/etc/init.d/install_gluster

MAX_DISKS=2

DISKS=$(fdisk -l 2>/dev/null | awk '$1 ~ /^Disk/ && $2 ~ /\/dev\// {print substr($2,0,length($2)-1)}')
NUM_DISKS=$(echo $DISKS|wc -w)

echo "INFO: found $NUM_DISKS disks"
if [[ $NUM_DISKS -gt $MAX_DISKS ]]; then echo "ERROR: more than $MAX_DISKS disks not supported" >&2; exit 1; fi

echo "INFO: creating new partiton"
sgdisk --new=4::-34 /dev/sda
DATA_DEV=/dev/sda4

if [[ $NUM_DISKS -eq 2 ]]; then
        DISK_SRC=/dev/sda
        DISK_DST=/dev/sdb

        echo "INFO: checking both disks are the same size"
        DISK_SRC_SZ=$(fdisk -l $DISK_SRC 2>/dev/null|awk '$1 ~ /^Disk/ && /bytes/ {printf "%s%s\n", $3, substr($4,0,length($4)-1)}')
        DISK_DST_SZ=$(fdisk -l $DISK_DST 2>/dev/null|awk '$1 ~ /^Disk/ && /bytes/ {printf "%s%s\n", $3, substr($4,0,length($4)-1)}')
        if [[ "$DISK_SRC_SZ" != "$DISK_DST_SZ" ]]; then echo "ERROR: $DISK_SRC is $DISK_SRC_SZ but $DISK_DST is $DISK_DST_SZ" >&2; exit 1; fi

        echo "INFO: encapsulating root partition"
        sgdisk --typecode=1:fd00 /dev/sda
        mdadm --create /dev/md0 --level=1 --raid-devices=2 --run --metadata=0.90 /dev/sda1 missing

        echo "INFO: encapsulating /var/log partition"
        sgdisk --typecode=5:fd00 /dev/sda
        mdadm --create /dev/md1 --level=1 --raid-devices=2 --run --metadata=0.90 /dev/sda5 missing

        echo "INFO: copying partition table to second disk"
        sgdisk -R /dev/sdb /dev/sda

        echo "INFO: mirroring root to second disk"
        mdadm -a /dev/md0 /dev/sdb1
        sleep 5
        grep -q recovery /proc/mdstat
        while [ $? -eq 0 ]; do
                sleep 5 
                grep -q recovery /proc/mdstat
        done
        resize2fs -f /dev/md0
        e2fsck -f /dev/md0

        echo "INFO: mirroring /var/log to second disk"
        mdadm -a /dev/md1 /dev/sdb5
        # not waiting for this one, let it run in the background

        # swap partition
        mdadm --create /dev/md2 --level=0 --raid-devices=2 --run --metadata=0.90 /dev/sda6 /dev/sdb6

        # data partition
        mdadm --create /dev/md3 --level=0 --raid-devices=2 --run --metadata=0.90 /dev/sda4 /dev/sdb4
        DATA_DEV=/dev/md3

        mount /dev/md0 /tmp/root
        mount -o bind /dev /tmp/root/dev
        mount -t sysfs none /tmp/root/sys
        mount -t proc none /tmp/root/proc
        mount -t tmpfs none /tmp/root/tmp
        mount -o bind /run /tmp/root/run

        cat > /tmp/root/etc/mdadm.conf <<-_EOF
MAILADDR root
auto +imsm +1.x -all
DEVICE /dev/sd*[a-z][1-9]
_EOF
        mdadm --detail --scan >> /tmp/root/etc/mdadm.conf

        SWAP_LABEL=$(awk '$2 ~ /^swap$/ {print substr($1,7)}' /tmp/root/etc/fstab)

        sed -i 's/quiet/rd.auto rd.auto=1/' /tmp/root/boot/grub/grub.cfg

        chroot /tmp/root grub-install /dev/sdb
        chroot /tmp/root dracut --mdadm --fstab --add='dm mdraid' --filesystems ext3 --add-drivers='raid1 raid0' --force /boot/initrd-`uname -r`.img `uname -r` -M

 # wait until /var/log resync done before wrapping up
        sleep 5
        grep -q recovery /proc/mdstat
        while [ $? -eq 0 ]; do
                sleep 5 
                grep -q recovery /proc/mdstat
        done
        resize2fs -f /dev/md1
 e2fsck -f /dev/md1

        mkswap -L $SWAP_LABEL /dev/md2
else
        mount /dev/sda1 /tmp/root
        mount /dev/sda5 /tmp/root/var/log
        mount -o bind /dev /tmp/root/dev
        mount -t sysfs none /tmp/root/sys
        mount -t proc none /tmp/root/proc
        mount -t tmpfs none /tmp/root/tmp
        mount -o bind /run /tmp/root/run
fi

# first boot init script that will create a sr based on the new storage volume
cat > /tmp/root/$FIRSTBOOT_INIT1 <<_EOF
#!/bin/bash
# chkconfig: 3 99 99
# description: xs_create_sr
echo "INFO: creating storage repository"
/opt/xensource/bin/xe sr-create content-type=user type=ext device-config:device=$DATA_DEV shared=false name-label="Local storage"
rm -f $FIRSTBOOT_INIT1
_EOF

chmod +x /tmp/root/$FIRSTBOOT_INIT1
chroot /tmp/root /usr/sbin/chkconfig --add $FIRSTBOOT_INIT1

# first boot init script that will install gluster server
cat > /tmp/root/$FIRSTBOOT_INIT2 <<_EOF
#!/bin/bash
# chkconfig: 3 99 99
# description: gluster_inst
echo "INFO: installing gluster"
sleep 15 # let networking kick in ?
sed -i 's/enabled=0/enabled=1/' /etc/yum.repos.d/CentOS-Base.repo
rpm  -ivh  http://dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-9.noarch.rpm
wget -P /etc/yum.repos.d https://download.gluster.org/pub/gluster/glusterfs/3.7/LATEST/CentOS/glusterfs-epel.repo
yum --releasever=7 -y install glusterfs glusterfs-fuse glusterfs-server
systemctl start glusterd.service
rm -f $FIRSTBOOT_INIT2
_EOF

chmod +x /tmp/root/$FIRSTBOOT_INIT2
chroot /tmp/root /usr/sbin/chkconfig --add $FIRSTBOOT_INIT2

umount /tmp/root/{run,tmp,proc,sys,dev,}
sync;sync
exit 0

xenserver.ks.xml

<installation mode="fresh" srtype="lvm">
    <keymap>us</keymap>
    <primary-disk gueststorage="no">sda</primary-disk>
    <source type="url">http://$server/cblr/links/$distro</source>
    <root-password>password</root-password>

    <script stage="installation-complete" type="url">http://$server/cblr/aux/xenserver/post-install</script>

    <admin-interface name="eth0" proto="static">
        #set $nic     = $interfaces["eth0"]
        #set $ip      = $nic["ip_address"]
        #set $netmask = $nic["netmask"]
        <ip>$ip</ip>
        <subnet-mask>$netmask</subnet-mask>
        <gateway>$gateway</gateway>
    </admin-interface>
    <name-server>192.168.1.254</name-server>

    <timezone>Europe/London</timezone>
    <hostname>$hostname</hostname>

    <time-config-method>ntp</time-config-method>
    <ntp-server>17.254.34.125</ntp-server>

</installation>

xenserver.sh

#!/bin/bash
#
# this file goes into: /var/lib/cobbler/triggers/sync/post to clean up after cobbler sync runs.
#
# largely based on http://ikenticustech.blogspot.co.uk/2011/04/xenserver-citrix-cobbler-part-one.html
# but updated for xenserver7

libdir=/var/lib/cobbler
srcdir=/var/www/cobbler
dstdir=/var/lib/tftpboot

for profile in $( grep -l xenserver7.ks $libdir/config/profiles.d/* ); do
    json=${profile##*/}
    name=${json%.json}
    [[ -d $dstdir/images/$name ]] && rsync -avq $srcdir/ks_mirror/$name/{install.img,boot/vmlinuz} $dstdir/images/$name/
done

# xenserver7 needs 1024M memory, any less and you will get errors during the yum phase
for file in $( grep -l xen.gz $dstdir/pxelinux.cfg/* ); do
    sed -i'' -e 's!initrd=\(/images/.*/\)\(xen.gz \)ks.*ks=\(.*\)$!\1\2dom0_mem=1024M com1=115200,8n1 console=com1,vga --- \1vmlinuz xencons=hvc console=hvc0 console=tty0 answerfile=\3 install --- \1install.img!;' $file
done

if you use cobbler, you wont be able to use the /var/lib/tftpboot/pxelinux.0 that comes with cobbler with xenserver, as the mboot.c32 file that xenserver wants to use is incompatible and the pxe process will hang.. you will need to use the pxelinux.0 in /var/www/cobbler/ks_mirror/XenServer-7.0.0/boot/pxelinux (when you cobbler import) the distro..