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diff --git a/src/ceph/src/script/run_uml.sh b/src/ceph/src/script/run_uml.sh
new file mode 100755
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+++ b/src/ceph/src/script/run_uml.sh
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+#!/bin/bash -norc
+
+# Magic startup script for a UML instance.  As long as unique
+# instances are started, more than one of them can be concurrently
+# in use on a single system.  All their network interfaces are
+# bridged together onto the virtual bridge "virbr0" which is
+# supplied by the "libvirt" package.
+#
+# Note that a DHCP server is started for that interface.  It's
+# configured in this file:
+#	/etc/libvirt/qemu/networks/default.xml
+# Unfortunately what I see there serves all possible DHCP addresses,
+# so stealing them like we do here isn't really kosher.  To fix
+# it, that configuration should change to serve a smaller subset
+# of the available address range.
+#
+# Each instance uses its own tun/tap device, created using the
+# "tunctl" command.  The assigned tap device will correspond with
+# the guest id (a small integer representing the instance), i.e.,
+# guest id 1 uses tap1, etc.  The tap device is attached to the
+# virtual bridge, which will have its own subnet associated with it.
+# The guest side of that interface will have the same subnet as the
+# bridge interface, with the bottom bits representing (normally) 100
+# more than the guest id.  So for subnet 192.168.122.0/24, guest
+# id 1 will use ip 192.168.122.101, guest id 2 will use ip
+# 192.168.122.102, and so on.  Because these interfaces are bridged,
+# they can all communicate with each other.
+
+# You will want to override this by setting and exporting the
+# "CEPH_TOP" environment variable to be the directory that contains
+# the "ceph-client" source tree.
+CEPH_TOP="${CEPH_TOP:-/home/elder/ceph}"
+
+# You may want to change this too, if you want guest UML instances
+# to have a diffeerent IP address range.  The guest IP will be based
+# on this plus GUEST_ID (defined below).
+GUEST_IP_OFFSET="${GUEST_IP_OFFSET:-100}"
+
+#############################
+
+if [ $# -gt 1 ]; then
+	echo "" >&2
+	echo "Usage: $(basename $0) [guest_id]" >&2
+	echo "" >&2
+	echo "    guest_id is a small integer (default 1)" >&2
+	echo "    (each UML instance needs a distinct guest_id)" >&2
+	echo "" >&2
+	exit 1
+elif [ $# -eq 1 ]; then
+	GUEST_ID="$1"
+else
+	GUEST_ID=1
+fi
+
+# This will be what the guest host calls itself.
+GUEST_HOSTNAME="uml-${GUEST_ID}"
+
+# This is the path to the boot disk image used by UML.
+DISK_IMAGE_A="${CEPH_TOP}/ceph-client/uml.${GUEST_ID}"
+if [ ! -f "${DISK_IMAGE_A}" ]; then
+	echo "root disk image not found (or not a file)" >&2
+	exit 2
+fi
+
+# Hostid 1 uses tun/tap device tap1, hostid 2 uses tap2, etc.
+TAP_ID="${GUEST_ID}"
+# This is the tap device used for this UML instance
+TAP="tap${TAP_ID}"
+
+# This is just used to mount an image temporarily
+TMP_MNT="/tmp/m$$"
+
+# Where to put a config file generated for this tap device
+TAP_IFUPDOWN_CONFIG="/tmp/interface-${TAP}"
+
+# Compute the HOST_IP and BROADCAST address values to use,
+# and assign shell variables with those names to their values.
+# Also compute BITS, which is the network prefix length used.
+# The NETMASK is then computed using that BITS value.
+eval $(
+ip addr show virbr0 | awk '
+/inet/ {
+	split($2, a, "/")
+	printf("HOST_IP=%s\n", a[1]);
+	printf("BROADCAST=%s\n", $4);
+	printf("BITS=%s\n", a[2]);
+	exit(0);
+}')
+
+# Use bc to avoid 32-bit wrap when computing netmask
+eval $(
+echo -n "NETMASK="
+bc <<! | fmt | sed 's/ /./g'
+m = 2 ^ 32 - 2 ^ (32 - ${BITS})
+for (p = 24; p >= 0; p = p - 8)
+    m / (2 ^ p) % 256
+!
+)
+
+# Now use the netmask and the host IP to compute the subnet address
+# and from that the guest IP address to use.
+eval $(
+awk '
+function from_quad(addr,  a, val, i) {
+	if (split(addr, a, ".") != 4)
+		exit(1);	# address not in dotted quad format
+	val = 0;
+	for (i = 1; i <= 4; i++)
+		val = val * 256 + a[i];
+	return val;
+}
+function to_quad(val,  addr, i) {
+	addr = "";
+	for (i = 1; i <= 4; i++) {
+		addr = sprintf("%u%s%s", val % 256, i > 1 ? "." : "", addr);
+		val = int(val / 256);
+	}
+	if ((val + 0) != 0)
+		exit(1);	# value provided exceeded 32 bits
+	return addr;
+}
+BEGIN {
+	host_ip = from_quad("'${HOST_IP}'");
+	netmask = from_quad("'${NETMASK}'");
+	guest_net_ip = '${GUEST_IP_OFFSET}' + '${GUEST_ID}';
+	if (and(netmask, guest_net_ip))
+		exit(1);	# address too big for subnet
+	subnet = and(host_ip, netmask);
+	guest_ip = or(subnet, guest_net_ip);
+	if (guest_ip == host_ip)
+		exit(1);	# computed guest ip matches host ip
+
+	printf("SUBNET=%s\n", to_quad(subnet));
+	printf("GUEST_IP=%s\n", to_quad(guest_ip));
+}
+' < /dev/null
+)
+
+############## OK, we now know all our network parameters...
+
+# There is a series of things that need to be done as superuser,
+# so group them all into one big (and sort of nested!) sudo request.
+sudo -s <<EnD_Of_sUdO
+# Mount the boot disk for the UML and set up some configuration
+# files there.
+mkdir -p "${TMP_MNT}"
+mount -o loop "${DISK_IMAGE_A}" "${TMP_MNT}"
+
+# Arrange for loopback and eth0 to load automatically,
+# and for eth0 to have our desired network parameters.
+cat > "${TMP_MNT}/etc/network/interfaces" <<!
+# Used by ifup(8) and ifdown(8). See the interfaces(5) manpage or
+# /usr/share/doc/ifupdown/examples for more information.
+auto lo
+iface lo inet loopback
+auto eth0
+# iface eth0 inet dhcp
+iface eth0 inet static
+        address ${GUEST_IP}
+        netmask ${NETMASK}
+        broadcast ${BROADCAST}
+        gateway ${HOST_IP}
+!
+
+# Have the guest start with an appropriate host name.
+# Also record an entry for it in its own hosts file.
+echo "${GUEST_HOSTNAME}" > "${TMP_MNT}/etc/hostname"
+echo "${GUEST_IP}	${GUEST_HOSTNAME}" >> "${TMP_MNT}/etc/hosts"
+
+# The host will serve as the name server also
+cat > "${TMP_MNT}/etc/resolv.conf" <<!
+nameserver ${HOST_IP}
+!
+
+# OK, done tweaking the boot image.
+sync
+umount "${DISK_IMAGE_A}"
+rmdir "${TMP_MNT}"
+
+# Set up a config file for "ifup" and "ifdown" (on the host) to use.
+# All the backslashes below are needed because we're sitting inside
+# a double here-document...
+cat > "${TAP_IFUPDOWN_CONFIG}" <<!
+iface ${TAP} inet manual
+	up brctl addif virbr0 "\\\${IFACE}"
+	up ip link set dev "\\\${IFACE}" up
+	pre-down brctl delif virbr0 "\\\${IFACE}"
+	pre-down ip link del dev "\\\${IFACE}"
+	tunctl_user $(whoami)
+!
+
+# OK, bring up the tap device using our config file
+ifup -i "${TAP_IFUPDOWN_CONFIG}" "${TAP}"
+
+EnD_Of_sUdO
+
+# Finally ready to launch the UML instance.
+./linux \
+	umid="${GUEST_HOSTNAME}" \
+	ubda="${DISK_IMAGE_A}" \
+	eth0="tuntap,${TAP}" \
+	mem=1024M
+
+# When we're done, clean up.  Bring down the tap interface and
+# delete the config file.
+#
+# Note that if the above "./linux" crashes, you'll need to run the
+# following commands manually in order to clean up state.
+sudo ifdown -i "${TAP_IFUPDOWN_CONFIG}" "${TAP}"
+sudo rm -f "${TAP_IFUPDOWN_CONFIG}"
+
+exit 0