From 427f1eb9b23d208d1ff2ba8ce12ddf7821dcd89f Mon Sep 17 00:00:00 2001
From: Nikos Skalkotos <skalkoto@grnet.gr>
Date: Mon, 3 Nov 2014 17:36:31 +0200
Subject: [PATCH] Use the device mapper to snapshot raw images
Do not use qcow2 to snapshot images that are raw. qemu-nbd is not
present in some old systems like CentOS 6.x. All we can do to support
those systems is to use the device mapper in as many cases as possible.
---
image_creator/disk.py | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/image_creator/disk.py b/image_creator/disk.py
index 3e13446..af3b2f3 100644
--- a/image_creator/disk.py
+++ b/image_creator/disk.py
@@ -18,7 +18,7 @@
"""Module hosting the Disk class."""
from image_creator.util import get_command, try_fail_repeat, free_space, \
- FatalError, create_snapshot
+ FatalError, create_snapshot, image_info
from image_creator.bundle_volume import BundleVolume
from image_creator.image import Image
@@ -157,19 +157,21 @@ class Disk(object):
return self.file
# Examine media file
- mode = os.stat(self.file).st_mode
+ info = image_info(self.file)
self.out.output("Snapshotting media source ...", False)
- # Create a qcow2 snapshot for image files
- if not stat.S_ISBLK(mode):
+ # Create a qcow2 snapshot for image files that are not raw
+ if info['format'] != 'raw':
snapshot = create_snapshot(self.file, self.tmp)
self._add_cleanup(os.unlink, snapshot)
self.out.success('done')
return snapshot
- # Create a device-mapper snapshot for block devices
- size = int(blockdev('--getsz', self.file))
+ # Create a device-mapper snapshot for raw image files and block devices
+ mode = os.stat(self.file).st_mode
+ device = self.file if stat.S_ISBLK(mode) else self._losetup(self.file)
+ size = int(blockdev('--getsz', device))
cowfd, cow = tempfile.mkstemp(dir=self.tmp)
os.close(cowfd)
@@ -183,7 +185,7 @@ class Disk(object):
try:
try:
os.write(tablefd, "0 %d snapshot %s %s n 8\n" %
- (size, self.file, cowdev))
+ (size, device, cowdev))
finally:
os.close(tablefd)
@@ -196,7 +198,6 @@ class Disk(object):
def get_image(self, media, **kwargs):
"""Returns a newly created Image instance."""
-
image = Image(media, self.out, **kwargs)
self._images.append(image)
image.enable()
--
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