Add DR virtualization scenario (#3615)

Co-authored-by: Maximilian Kolb <mail@maximilian-kolb.de>
Co-authored-by: Evgeni Golov <evgeni@golov.de>

guides/common/assembly_disaster-recovery-by-virtualizing-your-projectserver.adoc

@@ -0,0 +1,9 @@
+include::modules/con_disaster-recovery-by-virtualizing-your-projectserver.adoc[]
+
+include::modules/ref_prerequisites-disaster-recovery-by-virtualizing-your-projectserver.adoc[leveloffset=+1]
+
+include::modules/proc_preparing-for-disaster-recovery-by-virtualizing-your-projectserver.adoc[leveloffset=+1]
+
+include::modules/proc_recovering-from-disaster-by-restoring-a-vm-snapshot-of-projectserver.adoc[leveloffset=+1]
+
+include::modules/proc_retrieving-status-of-services.adoc[leveloffset=+1]

guides/common/assembly_preparing-for-disaster-recovery-and-recovering-from-data-loss.adoc

@@ -1,3 +1,5 @@
 include::modules/con_preparing-for-disaster-recovery-and-recovering-from-data-loss.adoc[]
 
 include::modules/con_overview-of-recommended-disaster-recovery-plans.adoc[leveloffset=+1]
+
+include::assembly_disaster-recovery-by-virtualizing-your-projectserver.adoc[leveloffset=+1]

guides/common/modules/con_disaster-recovery-by-virtualizing-your-projectserver.adoc

@@ -0,0 +1,10 @@
+[id="disaster-recovery-by-virtualizing-your-{project-context}-server"]
+= Disaster recovery by virtualizing your {ProjectServer}
+
+If you virtualize your {ProjectServer} and ensure that you take regular snapshots of the virtual machine (VM), you can respond to various disaster scenarios by restoring your {Project} deployment from one of your snapshots.
+
+[NOTE]
+====
+The details for how to implement this scenario depend on your choice of a virtualization platform.
+Due to the variety of different hypervisors and their capabilities, {Team} does not provide detailed instructions for any specific virtualization platform.
+====

guides/common/modules/proc_preparing-for-disaster-recovery-by-virtualizing-your-projectserver.adoc

@@ -0,0 +1,27 @@
+[id="preparing-for-disaster-recovery-by-virtualizing-your-{project-context}-server"]
+= Preparing for disaster recovery by virtualizing your {ProjectServer}
+
+Implement a reliable process for regularly taking VM snapshots of your virtualized {ProjectServer} and for backing up your snapshots for long-term storage.
+
+.Procedure
+. Define a schedule for taking periodic snapshots of your virtualized {ProjectServer}.
+Consider your tolerance for potential data loss:
+Taking snapshots frequently will result in smaller amounts of data loss in case of a disaster.
+However, creating a snapshot takes time, and the snapshots also require storage space.
+. Define your snapshot retention policy.
+Consider how many snapshots you want to store: Regularly removing outdated snapshots helps optimize storage usage.
+. Using your hypervisor, schedule periodic snapshots of your {ProjectServer}.
+. Schedule periodic backups of the snapshots to prevent data loss in case of hypervisor failure.
++
+[NOTE]
+====
+While snapshots provide quick recovery points, backing up your snapshots gives you the ability for long-term storage and provides extra safety in case of a disaster on the side of your hypervisor.
+====
+. If you are using an external database that runs on a different machine than your {ProjectServer}, create snapshots and backups on the same schedule as your {ProjectServer}.
+
+.Verification
+. Verify that your hypervisor takes the snapshots according to the schedule that you defined.
+. Use the latest snapshot of your {ProjectServer} and restore it in an isolated environment.
+. To verify that you will be able to restore {Project} services in case of a disaster, assess the functionality of the test {ProjectServer}.
+See xref:Retrieving_the_Status_of_Services_{context}[].
+. Perform these verification checks regularly.

guides/common/modules/proc_recovering-from-disaster-by-restoring-a-vm-snapshot-of-projectserver.adoc

@@ -0,0 +1,17 @@
+[id="recovering-from-disaster-by-restoring-a-vm-snapshot-of-{project-context}-server"]
+= Recovering from disaster by restoring a VM snapshot of {ProjectServer}
+
+In case of a disaster, use a virtual machine (VM) snapshot of your {ProjectServer} to restore {Project} services.
+
+include::snip_disaster-recovery-hostname-cannot-change.adoc[]
+
+.Procedure
+. Identify the snapshot from which you want to recover.
+. Use hypervisor tools to restore from the selected snapshot.
+. If you are using an external database that runs on a different machine than your {ProjectServer}, ensure that you restore the database from a snapshot taken at the same time as or before the {ProjectServer} snapshot.
+. Update DNS records so that the {ProjectServer} hostname resolves to the new IP address.
+This redirects traffic from the old server to the new server and you will not need to re-register your hosts.
+
+.Verification
+* Assess the functionality of your restored {ProjectServer}.
+See xref:Retrieving_the_Status_of_Services_{context}[].

guides/common/modules/ref_prerequisites-disaster-recovery-by-virtualizing-your-projectserver.adoc

@@ -0,0 +1,5 @@
+[id="prerequisites-disaster-recovery-by-virtualizing-{project-context}-server"]
+= Prerequisites
+
+* Review xref:overview-of-recommended-disaster-recovery-plans[] to make sure that this disaster recovery plan works for you.
+* Your {ProjectServer} is deployed as a VM.

guides/common/modules/snip_disaster-recovery-hostname-cannot-change.adoc

@@ -0,0 +1,5 @@
+[IMPORTANT]
+====
+Ensure that the hostname of your {ProjectServer} does not change during recovery.
+The IP address can change.
+====

guides/doc-Administering_Project/master.adoc

@@ -60,7 +60,11 @@ include::common/assembly_using-foreman-webhooks.adoc[leveloffset=+1]
 
 include::common/assembly_searching-and-bookmarking.adoc[leveloffset=+1]
 
+:parent-context: {context}
+:context: disaster-recovery
 include::common/assembly_preparing-for-disaster-recovery-and-recovering-from-data-loss.adoc[leveloffset=+1]
+:context: {parent-context}
+:!parent-context:
 
 [appendix]
 ifdef::satellite[]