aboutsummaryrefslogtreecommitdiff
path: root/contrib/vm
diff options
context:
space:
mode:
authorMichael Brown <mcb30@ipxe.org>2010-09-22 16:14:09 +0100
committerMichael Brown <mcb30@ipxe.org>2010-09-22 16:26:18 +0100
commit45d066d4cd8bbb28aff7ce47202c7b494eedd5bd (patch)
tree9dcb68272d13683cf64a04df86af8e6cc4797f3e /contrib/vm
parent041f01e60106dcc9d64f4a82ab11236c589dc264 (diff)
downloadipxe-45d066d4cd8bbb28aff7ce47202c7b494eedd5bd.zip
ipxe-45d066d4cd8bbb28aff7ce47202c7b494eedd5bd.tar.gz
ipxe-45d066d4cd8bbb28aff7ce47202c7b494eedd5bd.tar.bz2
[contrib] Add script to easily create copy-on-write SAN images
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'contrib/vm')
-rwxr-xr-xcontrib/vm/cow48
1 files changed, 48 insertions, 0 deletions
diff --git a/contrib/vm/cow b/contrib/vm/cow
new file mode 100755
index 0000000..4abb8b8
--- /dev/null
+++ b/contrib/vm/cow
@@ -0,0 +1,48 @@
+#!/bin/sh
+
+set -e
+
+imgloop=
+tmpfile=
+tmploop=
+dmname=
+cowlink=
+
+function cleanup () {
+ set +e
+ [ -n "$cowlink" ] && rm $cowlink
+ [ -n "$dmname" ] && dmsetup remove $dmname
+ [ -n "$tmploop" ] && losetup -d $tmploop
+ [ -n "$tmpfile" ] && rm $tmpfile
+ [ -n "$imgloop" ] && losetup -d $imgloop
+}
+
+trap cleanup EXIT
+
+imgfile=$1
+if [ -z "$imgfile" ] ; then
+ echo Syntax: $0 /path/to/image/file
+ exit 1
+fi
+
+# Set up image loop device
+x=`losetup -f` ; losetup -r $x $imgfile ; imgloop=$x
+
+# Create temporary file and set up temporary loop device
+tmpfile=`mktemp $imgfile.XXXXXXXXXX`
+truncate -r $imgfile $tmpfile
+x=`losetup -f` ; losetup $x $tmpfile ; tmploop=$x
+
+# Create snapshot device
+imgsize=`blockdev --getsz $imgloop`
+x=`basename $imgfile` ; echo 0 $imgsize snapshot $imgloop $tmploop N 16 | \
+ dmsetup create $x ; dmname=$x
+chown --reference=$imgfile /dev/mapper/$dmname
+chmod --reference=$imgfile /dev/mapper/$dmname
+
+# Create symlink
+x=$imgfile.cow ; ln -s /dev/mapper/$dmname $x ; cowlink=$x
+
+# Wait until killed
+echo "Created $cowlink"
+while : ; do sleep 2147483647 ; done