But what if we have to move Virtual Machine instance from one platform to another
- OVF(Open Virtual Format) to AMI(Amazon Machine Image)
- VHD(Citrix Xen) to OVF or AMI
- etc..
I came across a supposed to be COOL tool to handle this (not free, but with a cost)
List of Virtual Image Formats
Raw
The "raw" image format is the simplest one, and is natively supported by both KVM and Xen hypervisors. You can think of a raw image as being the bit-equivalent of a block device file, created as if somebody had copied, say,/dev/sda
to a file using the
dd command. Note | |
---|---|
We don't recommend creating raw images by dd'ing block device files, we discuss how to create raw images later. |
The qcow2 (QEMU
copy-on-write version 2) format is commonly used with the KVM hypervisor. It has some
additional features over the raw format, such as:
Because qcow2 is sparse, it's often faster to convert a raw image to qcow2 and upload
it then to upload the raw file.
- Using sparse representation, so the image size is smaller
- Support for snapshots
Note | |
---|---|
Because raw images don't support snapshots, OpenStack Compute will automatically convert raw image files to qcow2 as needed. |
AMI/AKI/ARI
The AMI/AKI/ARI format was the initial image format supported by Amazon EC2. The image consists of three files:- AMI (Amazon Machine Image)
- This is a virtual machine image in raw format, as described above.
- AKI (Amazon Kernel Image)
- A kernel file that the hypervisor will load initially to boot the image. For a Linux machine, this would be a vmlinuz file.
- ARI (Amazon Ramdisk Image)
- An optional ramdisk file mounted at boot time. For a Linux machine, this would be an initrd file.
A UEC (Ubuntu Enterprise Cloud) tarball is a gzipped tarfile that contains an AMI
file, AKI file, and ARI file.
Note | |
---|---|
Ubuntu Enterprise Cloud refers to a discontinued Eucalyptus-based Ubuntu cloud solution that has been replaced by the OpenStack-based Ubuntu Cloud Infrastructure. |
VMWare's ESXi hypervisor uses the VMDK (Virtual Machine Disk) format for images.
VirtualBox uses the VDI (Virtual
Disk Image) format for image files. None of the OpenStack Compute hypervisors support
VDI directly, so you will need to convert these files to a different format to use them
with OpenStack.
The version of Hyper-V that ships with Microsoft Server 2012 uses the newer VHDX
format, which has some additional features over VHD such as support for larger disk
sizes and protection against data corruption during power failures.
OVF (Open Virtualization
Format) is a packaging format for virtual machines, defined by the Distributed
Management Task Force (DMTF) standards group. An OVF package contains one or more image
files, a .ovf XML metadata file that contains information about the virtual machine, and
possibly other files as well.
An OVF package can be distributed in different ways. For example, it could be distributed as a set of discrete files, or as a tar archive file with an .ova (open virtual appliance/application) extension.
OpenStack Compute does not currently have support for OVF packages, so you will need to extract the image file(s) from an OVF package if you wish to use it with OpenStack.
An OVF package can be distributed in different ways. For example, it could be distributed as a set of discrete files, or as a tar archive file with an .ova (open virtual appliance/application) extension.
OpenStack Compute does not currently have support for OVF packages, so you will need to extract the image file(s) from an OVF package if you wish to use it with OpenStack.
The ISO format is a disk image formatted with the read-only ISO 9660 (also known
as ECMA-119) filesystem commonly used for CDs and DVDs. While we don't normally think of
ISO a virtual machine image format, since ISOs contain bootable filesystems with an
installed operating system, you can treat them the same you treat other virtual machine
image files.
Thank you for your valuable content , Easy to understand and follow. As said, the migration to cloud is very essential for the protection of the database. cloud migration services
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