path: root/qemu-img.texi
AgeCommit message (Collapse)Author
2014-01-31Describe flaws in qcow/qcow2 encryption in the docsDaniel P. Berrange
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>
2014-01-24block: update block commit documentation regarding image truncationJeff Cody
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>
2014-01-24Documentation: qemu-img: Mention SIGUSR1 progress reportKevin Wolf
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>
2014-01-22docs: qcow2 compat=1.1 is now the defaultStefan Hajnoczi
Commit 9117b47717ad208b12786ce88eacb013f9b3dd1c ("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>
2013-12-20docs: updated qemu-img man page and qemu-doc to reflect VHDX support.Jeff Cody
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>
2013-12-04qemu-img: add -l for snapshot in convertWenchao Xia
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>
2013-11-28qemu-img: add support for fully allocated imagesPeter Lieven
Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-12block: Image file option amendmentMax Reitz
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>
2013-09-06docs, qapi: document qemu-img mapPaolo Bonzini
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>
2013-09-06add qemu-img convert -n option (skip target volume creation)Alexandre Derumier
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>
2013-02-22qemu-img: Add compare subcommandMiroslav Rezanina
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>
2013-02-22qemu-img: Add "Quiet mode" optionMiroslav Rezanina
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>
2013-02-22qemu-img: add json output option to the check commandFederico Simoncelli
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>
2012-11-30Documentation: Update image format informationKevin Wolf
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>
2012-10-24qemu-img: document 'info --backing-chain'Kashyap Chamarthy
Signed-off-by: Kashyap Chamarthy <kashyap.cv@gmail.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-10-24qemu-img rebase: use empty string to rebase without backing fileAlex Bligh
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>
2012-09-17Merge remote-tracking branch 'kwolf/for-anthony' into stagingAnthony Liguori
* 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
2012-09-14Spelling fixes in comments and documentationStefan Weil
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>
2012-09-12qemu-img: Add json output option to the info command.Benoît Canet
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>
2012-08-17Documentation: Warn against qemu-img on active imageKevin Wolf
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>
2012-06-15qemu-img: document qed format on qemu-img man pageStefan Hajnoczi
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>
2012-06-15qemu-img check -r for repairing imagesKevin Wolf
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>
2012-05-25qemu-img: Explain how rebase operation can be used to perform a 'diff' ↵Richard W.M. Jones
operation. Signed-off-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-15Documentation: Add qemu-img -t parameter in man pageKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-08-29qemu-img: Require larger zero areas for sparse handlingKevin Wolf
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>
2011-07-20Add missing documentation for qemu-img -pJes Sorensen
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-07-05Documentation: Remove outdated host_device noteKevin Wolf
People shouldn't explicitly specify host_device any more. raw is doing the Right Thing. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-01-24Documentation: Add qemu-img check/rebaseKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-10-22Copy snapshots out of QCOW2 diskedison
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>
2010-05-03qemu-img: Add 'resize' command to grow/shrink disk imagesStefan Hajnoczi
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>
2009-11-09Documentation: Add options to image format descriptionsKevin Wolf
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>
2009-11-09Documentation: Don't mention old qemu-img optionsKevin Wolf
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>
2009-11-09Documentation: Move image format descriptions to own sectionKevin Wolf
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>
2009-10-06add host_device format description to qemu-img manpageAdrian Bridgett
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>
2009-08-10Add new block driver for the VDI format (only aio supported)Stefan Weil
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:
2009-06-07Use hxtool for qemu-img command listStuart Brady
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>
2009-06-06Document changes in qemu-img interfaceKevin Wolf
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>
2009-03-28qemu-img: adding a "-F base_fmt" option to "qemu-img create -b" (Uri Lublin)aliguori
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
2009-01-24Synch code, help and docsblueswir1
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
2008-06-05New qemu-img convert -B option, by Marc Bevand.ths
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4672 c046a42c-6fe2-441c-8c8c-71466251a162
2008-06-05Update documentation for qemu-img convert options, by Marc Bevand.ths
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4671 c046a42c-6fe2-441c-8c8c-71466251a162
2007-09-16vmdk compatibility level 6 images, by Soren Hansen.ths
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3175 c046a42c-6fe2-441c-8c8c-71466251a162
2007-09-16find -type f | xargs sed -i 's/[\t ]$//g' # on most filesths
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3173 c046a42c-6fe2-441c-8c8c-71466251a162
2007-06-03Documentation spelling fixes, by Mark Glines.ths
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2928 c046a42c-6fe2-441c-8c8c-71466251a162
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2100 c046a42c-6fe2-441c-8c8c-71466251a162
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@1518 c046a42c-6fe2-441c-8c8c-71466251a162
2004-11-15doc update - added qemu-img manual pagebellard
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@1151 c046a42c-6fe2-441c-8c8c-71466251a162