For more informations regarding uploading own images in OpenStack, please refer to this article. By continuing to use the site you are agreeing to our use of cookies.
If you do not agree with the terms and conditions, please do not use the website. Learn More A-B A-B 2 2 gold badges 6 6 silver badges 17 17 bronze badges. I'd use a raw base-image and overlay QED instead of qcow2. QED is faster than qcow2 and less likely to be corrupted by design. Matt please comment on the edited question. The performance differences are interesting. Can you try it with qed? I believe it has some problems which is why they invented qed.
Matt I checked with raw baseimage-qed overlay and raw baseimage-qcow2 overlay. But qed is much slower than qcow2 in this setting. Add a comment. Active Oldest Votes. Anyway, I found Qcow2 files somewhat fragile.
Improve this answer. As stated above: individual RAW images are going to be faster due to no indirection layers. Remember that you are giving up snapshots at image level and space efficiency, however. Moreover, I'm under the impression that your third result was skewed by host cache. Actually I was thinking the same. But then I thought that, in case of actual use also it will follow the same flow. Linux Install qemu-img. For Ubuntu or Debian, run the following command: apt install qemu-img For CentOS, Red Hat, or Oracle, run the following command: yum install qemu-img For SUSE or openSUSE, run the following command: zypper install qemu-img Run the following command to check whether the installation is successful: qemu-img -v If the version information and help manual of the qemu-img tool are contained in the command output, the installation is successful.
The following information is displayed: [root CentOS7 home] qemu-img convert -p -f vmdk -O qcow2 centos6. Examples A pre-allocated image depends on two files: xxxx. Run the following commands to query the image file details: ls -lh centos6. Parent topic: Converting the Image Format. Did you find this page helpful?
Submit successfully! Failed to submit the feedback. You can also use "-o options " to specify various options, such as: back-end image, file size, whether to encrypt and so on. At this time, the content of the back-end image specified in the conversion command must be the same as that of the input file, although The directories and formats of their respective back-end mirrors may be different.
If you use qcow2, qcow, cow, etc. The following command line demonstrates two conversions: converting VMware's vmdk format image to a qcow2 image that KVM can use, and converting a raw image file into a qcow2 format image. No vmdk file actually exists here, only its command line operation is demonstrated. Display the information of the filename image file. If the file is stored using a sparse file, it will also show its originally allocated size and the actual disk space occupied.
If a client snapshot is stored in the file, the snapshot information will also be displayed. The following command line demonstrates the input and output file information of the file conversion. The "-l" option is to query and list all the snapshots in the image file, "-a snapshot " is to let the image file use a snapshot, "-c snapshot " is to create a snapshot, "-d" is to delete a snapshot.
To change the back-end image file of the image file, only the qcow2 and qed formats support the rebase command. It can work in two modes, one is Safe Mode Safe Mode is also the default mode, qemu-img will compare the original back-end image with the current back-end image for reasonable processing; This is the Unsafe Mode, which is specified by the "-u" parameter.
This mode is mainly used to repair the front-end image file after renaming the back-end image or moving the location. Ensure the consistency of the back-end mirror. Change the size of the image file to be different from the size at the time of creation.
Before reducing the size of the image, you need to ensure that the file system in the client has free space, otherwise data will be lost. In addition, the qcow2 format file does not support the operation of reducing the image. After increasing the size of the image file, you also need to start the client to use the partition tools such as "fdisk" and "parted" to perform the corresponding operations to allow the client to use the increased image space.
However, you need to be careful when using the resize command it is best to make a backup. If it fails, it may cause the image file to be unusable and cause data loss.
The following command line demonstrates the change in the size of the two images: increasing a 1GB raw image by 2GB, and reducing a 3GB qcow2 image by 1G.
0コメント