Only create placeholder device when encryption is enabled

[jbaublitz]

Closes #3840

[packit-as-a-service]

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• sudo yum install -y dnf-plugins-core on RHEL 8
• sudo dnf install -y dnf-plugins-core on Fedora
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• And now you can install the packages.

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[packit-as-a-service]

Cockpit tests failed for commit a5b83bc. @martinpitt, @jelly, @mvollmer please check.

[packit-as-a-service]

Congratulations! One of the builds has completed. 🍾

You can install the built RPMs by following these steps:

• sudo yum install -y dnf-plugins-core on RHEL 8
• sudo dnf install -y dnf-plugins-core on Fedora
• dnf copr enable packit/stratis-storage-stratisd-3856
• And now you can install the packages.

Please note that the RPMs should be used only in a testing environment.

[packit-as-a-service]

Congratulations! One of the builds has completed. 🍾

You can install the built RPMs by following these steps:

• sudo yum install -y dnf-plugins-core on RHEL 8
• sudo dnf install -y dnf-plugins-core on Fedora
• dnf copr enable packit/stratis-storage-stratisd-3856
• And now you can install the packages.

Please note that the RPMs should be used only in a testing environment.

[packit-as-a-service]

Congratulations! One of the builds has completed. 🍾

You can install the built RPMs by following these steps:

• sudo yum install -y dnf-plugins-core on RHEL 8
• sudo dnf install -y dnf-plugins-core on Fedora
• dnf copr enable packit/stratis-storage-stratisd-3856
• And now you can install the packages.

Please note that the RPMs should be used only in a testing environment.

[jbaublitz]

@mulkieran Okay, I believe this is ready for review. The only tests that seem to be failing are the rawhide tests.

[jbaublitz]

After we just discussed this, this will likely be demoted to 3.9.0 or 3.9.1 depending on how hard it is to evaluate the need for migration code.

[jbaublitz]

Blocked by #3800

[jbaublitz]

@mulkieran I believe this may be rendered obsolete by the performance testing. I think the only thing we may need to test is slower drives. If there's a large performance degradation in V2, this may be worth pursuing.

[jbaublitz]

I confirmed with @spetrovi that performance is consistent across slower and faster drives. I'm going to close the linked issue.