casper zram

--- casper.orig 2012-05-17 12:48:23.786986671 -0400
+++ casper  2012-05-17 13:19:54.204228445 -0400
@@ -142,6 +142,13 @@ is_nice_device() {
     return 1
 }

+# Load zram if not loaded
+load_zram() {
+   if [ ! -b /dev/zram0 ]; then
+       modprobe zram zram_num_devices=4
+   fi
+}
+
 copy_live_to() {
     copyfrom="${1}"
     copytodev="${2}"
@@ -151,11 +158,22 @@ copy_live_to() {

     if [ "${copytodev}" = "ram" ]; then
         # copying to ram:
-        freespace=$(awk '/^MemFree:/{f=$2} /^Cached:/{c=$2} END{print f+c}' /proc/meminfo)
-        mount_options="-o size=${size}k"
+        freespace=$(awk '/^MemTotal:/{f=$2} END{print f / 2}' /proc/meminfo)
+        mount_options=""
         free_string="memory"
-        fstype="tmpfs"
-        dev="/dev/shm"
+        fstype="ext2"
+   # zram0 reserved for swap, so use zram1
+        dev="/dev/zram1"
+   # Load if not loaded
+   load_zram
+   # If we didn't load enough, that's a problem
+   if [ ! -b "${dev}" ]; then
+       [ "$quiet" != "y" ] && log_warning_msg "${dev} is not a block device (zram loaded without zram_num_devices high enough?)."
+       return 1
+   fi
+   # Because of file system overhead, add 10%
+   echo $(( freespace * 1024 * 11 / 10 )) > /sys/block/zram1/disksize
+   mkfs.ext2 "${dev}"
     else
         # it should be a writable block device
         if [ -b "${copytodev}" ]; then
@@ -425,10 +443,11 @@ setup_unionfs() {
     rofsstring=${rofsstring%:}

     mkdir -p /cow
-    cowdevice="tmpfs"
-    cow_fstype="tmpfs"
+    cowdevice="/dev/zram2"
+    cow_fstype="ext2"
     cow_mountopt="rw,noatime,mode=755"

+
     # Looking for "${root_persistence}" device or file
     if [ -n "${PERSISTENT}" ]; then
         cowprobe=$(find_cow_device "${root_persistence}")
@@ -439,6 +458,16 @@ setup_unionfs() {
         else
             [ "$quiet" != "y" ] && log_warning_msg "Unable to find the persistent medium"
         fi
+    else
+   # Load if not loaded
+   load_zram
+   # If we didn't load enough, that's a problem
+   if [ ! -b "${cowdevice}" ]; then
+       [ "$quiet" != "y" ] && log_warning_msg "${cowdevice} is not a block device (zram loaded without zram_num_devices high enough?)."
+       return 1
+   fi
+   echo $(( freespace * 1024 )) > /sys/block/zram2/disksize
+   mkfs.ext2 "${cowdevice}"
     fi

     mount -t ${cow_fstype} -o ${cow_mountopt} ${cowdevice} /cow || panic "Can not mount $cowdevice on /cow"