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Mtv 2518 raw copy mode 2 #748

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2 changes: 2 additions & 0 deletions documentation/doc-Migration_Toolkit_for_Virtualization/master.adoc
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Expand Up @@ -591,6 +591,8 @@ include::modules/virt-migration-workflow.adoc[leveloffset=+3]

include::modules/virt-v2v-mtv.adoc[leveloffset=+3]

include::modules/raw-copy-mode.adoc[leveloffset=+3]

[id="logs-and-crs_{context}"]
=== Logs and custom resources

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27 changes: 27 additions & 0 deletions documentation/modules/raw-copy-mode.adoc
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// Module included in the following assemblies:
//
// * documentation/doc-Migration_Toolkit_for_Virtualization/master.adoc

:_content-type: CONCEPT
[id="raw-copy-mode_{context}"]
= Raw copy mode

[role="_abstract"]
In regular cold and warm migrations, {project-first} uses a program called `virt-v2v` to prepare virtual machines (VMs) for migration to {virt} after the VMs have been copied from their source provider.

The main function of `virt-v2v` is to convert the disk image of a VM into a format compatible with {virt}. This program is described in detail in xref:virt-v2v-mtv_mtv[How {project-short} uses the virt-v2v tool]. What is important to note here is that although `virt-v2v` is compatible with major operating systems such as recent versions of Red Hat Enterprise Linux, Windows, and Windows Server, it is not compatible with macOS and some other operating systems.

[NOTE]
====
For a list of the operating systems that `virt-v2v` supports, see link:https://access.redhat.com/articles/1351473[Converting virtual machines from other hypervisors to KVM with virt-v2v in RHEL 7, RHEL 8, and RHEL 9].
====

As a workaround for migrating VMs that use an operating system that `virt-v2v` does not support, {project-short} includes a feature called _raw copy mode_. Raw copy mode copies VMs without applying any tool to convert them for use with {virt}. The migrated VMs use emulated devices.

This enables more robust migrations, enabling a wider range of operating systems and configurations. Examples are VMs with uncommon file systems, VMs with uncommon encryption technologies or without access to keys.

However, VMs migrated using raw copy mode raw copy mode might not boot on {virt} or perform as well as VMs migrated in the regular way. VMs migrated using raw copy mode might not boot on {virt} or perform as well as VMs migrated in the regular way.

Therefore, using raw copy mode is a tradeoff between being a more versatile migration option compared to increasing the risk of problems following migration.

Because of this risk, users are asked to request that Red Hat support perform raw copy mode migrations.