Commit Graph

47 Commits

Author SHA1 Message Date
Daniel P. Berrange 136cd19d05 Describe flaws in qcow/qcow2 encryption in the docs
The qemu-img.texi / qemu-doc.texi files currently describe the
qcow2/qcow2 encryption thus

  "Encryption uses the AES format which is very secure (128 bit
   keys). Use a long password (16 characters) to get maximum
   protection."

While AES is indeed a strong encryption system, the way that
QCow/QCow2 use it results in a poor/weak encryption system.
Due to the use of predictable IVs, based on the sector number
extended to 128 bits, it is vulnerable to chosen plaintext
attacks which can reveal the existence of encrypted data.

The direct use of the user passphrase as the encryption key
also leads to an inability to change the passphrase of an
image. If passphrase is ever compromised the image data will
all be vulnerable, since it cannot be re-encrypted. The admin
has to clone the image files with a new passphrase and then
use a program like shred to secure erase all the old files.

Recommend against any use of QCow/QCow2 encryption, directing
users to dm-crypt / LUKS which can meet modern cryptography
best practices.

[Changed "Qcow" to "qcow" for consistency.
--Stefan]

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-01-31 22:05:03 +01:00
Jeff Cody 3722290074 block: update block commit documentation regarding image truncation
This updates the documentation for commiting snapshot images.
Specifically, this highlights what happens when the base image
is either smaller or larger than the snapshot image being committed.

In the case of the base image being smaller, it is resized to the
larger size of the snapshot image.  In the case of the base image
being larger, it is not resized automatically, but once the commit
has completed it is safe for the user to truncate the base image.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-01-24 16:12:49 +01:00
Kevin Wolf 0e3bd9932f Documentation: qemu-img: Mention SIGUSR1 progress report
Document the SIGUSR1 behaviour of qemu-img. Also, added compare to the
list of subcommands that support -p.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
2014-01-24 14:33:00 +01:00
Stefan Hajnoczi 7fa9e1f941 docs: qcow2 compat=1.1 is now the default
Commit 9117b47717 ("qcow2: Change default
for new images to compat=1.1") changed the default qcow2 image format
version but forgot to update qemu-doc.texi and qemu-img.texi.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-01-22 12:07:16 +01:00
Jeff Cody 8282db1b2e docs: updated qemu-img man page and qemu-doc to reflect VHDX support.
The man page for qemu-img, and the qemu-doc, did not mention VHDX
as a supported format.  This adds in reference to VHDX in those
documents.

[Stefan Weil <sw@weilnetz.de> suggested s/Block Size/Block size/ for
consistency.  I have made this change.
--Stefan]

Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-12-20 09:11:58 +01:00
Wenchao Xia ef80654d0d qemu-img: add -l for snapshot in convert
Now qemu-img convert have similar options as qemu-nbd for internal
snapshot.

Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-12-04 15:19:00 +01:00
Peter Lieven 11b6699af5 qemu-img: add support for fully allocated images
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-11-28 10:30:52 +01:00
Max Reitz 6f176b48f9 block: Image file option amendment
This patch adds the "amend" option to qemu-img which allows changing
image options on existing image files. It also adds the generic bdrv
implementation which is basically just a wrapper for the image format
specific function.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-12 10:12:46 +02:00
Paolo Bonzini facd6e2b5c docs, qapi: document qemu-img map
Eric Blake also requested including the output in qapi-schema.json,
so that it is published through the introspection mechanism.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06 15:25:09 +02:00
Alexandre Derumier b2e10493c7 add qemu-img convert -n option (skip target volume creation)
Add a -n option to skip volume creation on qemu-img convert.
This is useful for targets such as rbd / ceph, where the
target volume may already exist; we cannot always rely on
qemu-img convert to create the image, as dependent on the
output format, there may be parameters which are not possible
to specify through the qemu-img convert command line.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Alexandre Derumier <aderumier@odiso.com>
Signed-off-by: Alex Bligh <alex@alex.org.uk>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06 15:25:07 +02:00
Miroslav Rezanina d14ed18c8d qemu-img: Add compare subcommand
This patch adds new qemu-img subcommand that compares content of two disk
images.

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-22 21:21:10 +01:00
Miroslav Rezanina f382d43a91 qemu-img: Add "Quiet mode" option
There can be a need to turn output to stdout off. This patch adds a -q option
that enable "Quiet mode". In Quiet mode, only errors are printed out.

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-22 21:21:09 +01:00
Federico Simoncelli 8599ea4c42 qemu-img: add json output option to the check command
This option --output=[human|json] makes qemu-img check output a human
or JSON representation at the choice of the user.

Signed-off-by: Federico Simoncelli <fsimonce@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-02-22 21:21:08 +01:00
Kevin Wolf d3067b020b Documentation: Update image format information
Document new and yet undocumented options and image formats. The
qemu-img man page contains information only for raw and qcow2 now and
references the HTML documentation for a more detailed description of
other formats.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2012-11-30 11:33:24 +01:00
Kashyap Chamarthy e53575606a qemu-img: document 'info --backing-chain'
Signed-off-by: Kashyap Chamarthy <kashyap.cv@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-10-24 10:26:19 +02:00
Alex Bligh a616673dd1 qemu-img rebase: use empty string to rebase without backing file
This patch allows an empty filename to be passed as the new base image name
for qemu-img rebase to mean base the image on no backing file (i.e.
independent of any backing file). According to Eric Blake, qemu-img rebase
already supports this when '-u' is used; this adds support when -u is not
used.

Signed-off-by: Alex Bligh <alex@alex.org.uk>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-10-24 10:26:18 +02:00
Anthony Liguori 109820df4a Merge remote-tracking branch 'kwolf/for-anthony' into staging
* kwolf/for-anthony:
  block: Don't forget to delete temporary file
  Don't require encryption password for 'qemu-img info' command
  qemu-img: Add json output option to the info command.
  qapi: Add SnapshotInfo and ImageInfo.
  ahci: properly reset PxCMD on HBA reset
  block: fix block tray status
  vdi: Fix warning from clang
  block/curl: Fix wrong free statement
  ide: Fix error messages from static code analysis (no real error)
  ATAPI: STARTSTOPUNIT only eject/load media if powercondition is 0
  sheepdog: fix savevm and loadvm
2012-09-17 10:23:15 -05:00
Stefan Weil 0546b8c2f0 Spelling fixes in comments and documentation
These wrong spellings were detected by codespell:

* successully -> successfully

* alot -> a lot

* wanna -> want to

* infomation -> information

* occured -> occurred

["also is" -> "is also" and "ressources" -> "resources" suggested by
Peter Maydell <peter.maydell@linaro.org>]

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-09-14 08:21:28 +01:00
Benoît Canet c054b3fd78 qemu-img: Add json output option to the info command.
This option --output=[human|json] make qemu-img info output on
human or JSON representation at the choice of the user.

example:
{
    "snapshots": [
        {
            "vm-clock-nsec": 637102488,
            "name": "vm-20120821145509",
            "date-sec": 1345553709,
            "date-nsec": 220289000,
            "vm-clock-sec": 20,
            "id": "1",
            "vm-state-size": 96522745
        },
        {
            "vm-clock-nsec": 28210866,
            "name": "vm-20120821154059",
            "date-sec": 1345556459,
            "date-nsec": 171392000,
            "vm-clock-sec": 46,
            "id": "2",
            "vm-state-size": 101208714
        }
    ],
    "virtual-size": 1073741824,
    "filename": "snap.qcow2",
    "cluster-size": 65536,
    "format": "qcow2",
    "actual-size": 985587712,
    "dirty-flag": false
}

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-12 15:50:09 +02:00
Kevin Wolf 48467328c6 Documentation: Warn against qemu-img on active image
People have repeatedly expected that you can do things like snapshotting
an image with qemu-img while a qemu instance is running. Maybe we need
to consider locking the files while they are in use, but having a
warning in the qemu-img manpage is doable for 1.2 and can't hurt anyway.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-08-17 21:29:15 +02:00
Stefan Hajnoczi f085800e24 qemu-img: document qed format on qemu-img man page
The qemu-img.1 man page is missing the qed format from its list of
supported formats.  Document the image creation options for qed.

Suggested-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15 14:03:43 +02:00
Kevin Wolf 4534ff5426 qemu-img check -r for repairing images
The QED block driver already provides the functionality to not only
detect inconsistencies in images, but also fix them. However, this
functionality cannot be manually invoked with qemu-img, but the
check happens only automatically during bdrv_open().

This adds a -r switch to qemu-img check that allows manual invocation
of an image repair.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15 14:03:42 +02:00
Richard W.M. Jones 9fda6ab1d9 qemu-img: Explain how rebase operation can be used to perform a 'diff' operation.
Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-25 18:12:54 +02:00
Kevin Wolf 3763f26f2f Documentation: Add qemu-img -t parameter in man page
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-12-15 12:40:08 +01:00
Kevin Wolf a22f123ca3 qemu-img: Require larger zero areas for sparse handling
By default, require 4k of consecutive zero bytes for qemu-img to make the
output file sparse by not issuing a write request for the zeroed parts. Add an
-S option to allow users to tune this setting.

This helps to avoid situations where a lot of zero sectors and data sectors are
mixed and qemu-img tended to issue many tiny 512 byte writes.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-29 14:42:39 +02:00
Jes Sorensen aaf55b4795 Add missing documentation for qemu-img -p
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-07-20 11:13:52 +02:00
Kevin Wolf 02854532c2 Documentation: Remove outdated host_device note
People shouldn't explicitly specify host_device any more. raw is doing the
Right Thing.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-07-05 11:23:29 +02:00
Kevin Wolf e61846908e Documentation: Add qemu-img check/rebase
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-01-24 16:41:49 +01:00
edison 51ef67270b Copy snapshots out of QCOW2 disk
In order to backup snapshots, created from QCOW2 iamge, we want to copy snapshots out of QCOW2 disk to a seperate storage.
The following patch adds a new option in "qemu-img": qemu-img convert -f qcow2 -O qcow2 -s snapshot_name src_img bck_img.
Right now, it only supports to copy the full snapshot, delta snapshot is on the way.

Changes from V1: all the comments from Kevin are addressed:
Add read-only checking
Fix coding style
Change the name from bdrv_snapshot_load to bdrv_snapshot_load_tmp

Signed-off-by: Disheng Su <edison@cloud.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-10-22 14:49:35 +02:00
Stefan Hajnoczi ae6b0ed6d4 qemu-img: Add 'resize' command to grow/shrink disk images
This patch adds a 'resize' command to grow/shrink disk images.  This
allows changing the size of disk images without copying to a new image
file.  Currently only raw files support resize.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-03 10:07:32 +02:00
Kevin Wolf 3e03236438 Documentation: Add options to image format descriptions
Explain the existing format specific options that can be used with qemu-img
create/convert -o ...

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-11-09 08:43:12 -06:00
Kevin Wolf 8063d0fe3b Documentation: Don't mention old qemu-img options
The old options are still supported for compatibility, but they are
inconsistent (for example create -b vs. convert -B for backing files) and
incomplete (-F only exists for create) which tends to confuse people. Remove
all references to the old options from the documentation to guide users to the
more consistent -o options.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-11-09 08:43:12 -06:00
Kevin Wolf f932c04039 Documentation: Move image format descriptions to own section
The description of the image formats is too long to be a subitem of a parameter
description. It will become even longer when we include the options provided by
the respective format.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-11-09 08:43:12 -06:00
Adrian Bridgett a6af8e5f96 add host_device format description to qemu-img manpage
Converting files using "qemu-img convert" onto logical volumes (or any
block device) you need to use the currently undocumented "host_device"
format.  This patch adds the required documentation to the manpage.

Reported-by: Adrian Bridgett <adrian@bitcube.co.uk>
Signed-off-by: Adrian Bridgett <adrian@bitcube.co.uk>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-06 14:36:09 -05:00
Stefan Weil 9aebd98aab Add new block driver for the VDI format (only aio supported)
This is a new block driver written from scratch
to support the VDI format in QEMU.

VDI is the native format used by Innotek / SUN VirtualBox.

Latest changes:

* stripped down version
  (code for synchronous operations and experimental code removed)

* don't open VDI snapshot images (with uuid_link or uuid_parent)

* modified vdi_aio_cancel

Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Message-Id:
2009-08-10 13:05:30 -05:00
Stuart Brady 153859be1a Use hxtool for qemu-img command list
Use hxtool to generate the 'command syntax' section of qemu-img's help
message, and the corresponding section of the texinfo documentation.

This has the side-effect of adding 'check' to this list of commands in
the texinfo documentation.

Signed-off-by: Stuart Brady <stuart.brady@gmail.com>
2009-06-07 09:59:47 +03:00
Kevin Wolf eff442662d Document changes in qemu-img interface
Update the documentation to reflect the introduction of format specific options
with -o. Don't advertise -e or -6 any more, they exist only for compatibility
reasons and can be replaced by the corresponding -o options.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2009-06-06 18:39:02 +03:00
aliguori 9230eaf679 qemu-img: adding a "-F base_fmt" option to "qemu-img create -b" (Uri Lublin)
If the user specifies the backing file format,
then when opening the backing file, there is no need
to probe the (backing file) image to figure out its format.

This follows my previous patches implementing bdrv_create2
which keeps (for qcow2 only) the backing file format
as a qcow2-extension

Suggested by Daniel P. Berrange.

Signed-off-by: Uri Lublin <uril@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6910 c046a42c-6fe2-441c-8c8c-71466251a162
2009-03-28 17:55:19 +00:00
blueswir1 d2c639d6dc Synch code, help and docs
Rearrange code, help printout and docs so that they are in the same
(hopefully more logical) order for easier maintenance.

Add help and docs for undocumented options.

Reformat slightly for more consistent help output.

Add comments to encourage better synchronization in the future.


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6432 c046a42c-6fe2-441c-8c8c-71466251a162
2009-01-24 18:19:25 +00:00
ths f58c7b3545 New qemu-img convert -B option, by Marc Bevand.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4672 c046a42c-6fe2-441c-8c8c-71466251a162
2008-06-05 21:53:49 +00:00
ths ff7ab59f40 Update documentation for qemu-img convert options, by Marc Bevand.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4671 c046a42c-6fe2-441c-8c8c-71466251a162
2008-06-05 21:00:28 +00:00
ths ec36ba1474 vmdk compatibility level 6 images, by Soren Hansen.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3175 c046a42c-6fe2-441c-8c8c-71466251a162
2007-09-16 21:59:02 +00:00
ths 5fafdf24ef find -type f | xargs sed -i 's/[\t ]$//g' # on most files
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3173 c046a42c-6fe2-441c-8c8c-71466251a162
2007-09-16 21:08:06 +00:00
ths 4be456f126 Documentation spelling fixes, by Mark Glines.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2928 c046a42c-6fe2-441c-8c8c-71466251a162
2007-06-03 13:41:28 +00:00
bellard 19d36792c0 update
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2100 c046a42c-6fe2-441c-8c8c-71466251a162
2006-08-07 21:34:34 +00:00
bellard e5d80f94c5 update
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@1518 c046a42c-6fe2-441c-8c8c-71466251a162
2005-07-23 17:43:14 +00:00
bellard acd935ef62 doc update - added qemu-img manual page
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@1151 c046a42c-6fe2-441c-8c8c-71466251a162
2004-11-15 22:57:26 +00:00