Merge pull request #815 from k8up-io/change/docs

Update docs with RWO backup feature
k8up-io · Feb 28, 2023 · 6d8ab1d · 6d8ab1d
2 parents 3bc95d2 + a0f8b60
commit 6d8ab1d
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Showing 4 changed files with 15 additions and 3 deletions.
diff --git a/docs/docs.mk b/docs/docs.mk
@@ -18,7 +18,7 @@ asciidoctor_kindle_opts ?= --attribute ebook-format=kf8
 vale_cmd ?= $(docker_cmd) run $(docker_opts) --volume "$${PWD}"/src/modules/ROOT/pages:/pages vshn/vale:2.6.1 --minAlertLevel=error /pages
 hunspell_cmd ?= $(docker_cmd) run $(docker_opts) --volume "$${PWD}":/spell vshn/hunspell:1.7.0 -d en,vshn -l -H _public/**/**/*.html
 htmltest_cmd ?= $(docker_cmd) run $(docker_opts) --volume "$${PWD}"/_public:/test wjdp/htmltest:v0.12.0
-preview_cmd ?= $(docker_cmd) run --rm --publish 35729:35729 --publish 2020:2020 --volume "${PWD}":/preview/antora vshn/antora-preview:3.0.1.1 --antora=docs --style=k8up
+preview_cmd ?= $(docker_cmd) run --rm --publish 35729:35729 --publish 2020:2020 --volume "${PWD}":/preview/antora vshn/antora-preview:3.1.2.2 --antora=docs --style=k8up
 
 docs_usage_dir ?= docs/modules/ROOT/examples/usage
 

diff --git a/docs/modules/ROOT/nav.adoc b/docs/modules/ROOT/nav.adoc
@@ -37,6 +37,7 @@
 * xref:explanations/system-requirements.adoc[System Requirements]
 * xref:explanations/what-has-changed-in-v1.adoc[Changes in K8up v1.0]
 * xref:explanations/what-has-changed-in-v2.adoc[Changes in K8up v2.0]
+* xref:explanations/rwo.adoc[]
 
 .About
 * xref:about/roadmap.adoc[Roadmap]

diff --git a/docs/modules/ROOT/pages/explanations/rwo.adoc b/docs/modules/ROOT/pages/explanations/rwo.adoc
@@ -0,0 +1,13 @@
+= How RWO Backups are implemented
+
+K8s does not prevent mounting a RWO PVC to multiple pods, if they are scheduled on the same host.
+K8up uses this fact to provide the ability to back up RWO PVCs.
+
+For a given backup in a namespace K8up will list all the PVCs.
+The PVCs are then grouped depending on their type:
+
+* all RWX PVCs are grouped together
+* RWO PVCs are grouped by k8s node where they are currently mounted
+
+K8up will then deploy backup jobs according to the grouping, a single job for all RWX PVCs and a job for each K8s node.
+The jobs themselves work as before, they loop over the mounted PVCs and do a file backup via restic.
diff --git a/docs/modules/ROOT/pages/how-tos/prebackuppod.adoc b/docs/modules/ROOT/pages/how-tos/prebackuppod.adoc
@@ -2,15 +2,13 @@
 
 Although K8up supports xref:how-tos/application-aware-backups.adoc[executing backup commands] in already running pods, there might be a need to start a specific Pod for the backup.
 Like, what if the backup command you'd like to run isn't available in the running pod?
-Or maybe you want to backup something that's running on a RWO PVC?
 Or perhaps you want to backup something that's outside the Kubernetes cluster, like a managed cloud database?
 
 That's the perfect use case for using PreBackup pods!
 They're Pod definitions that live in your namespaces.
 Once the Operator triggers a backup for that specific namespace, then it will loop through all these Pod definitions, execute them and clean them up after the backup finished.
 They allow much more flexibility, as they support everything a normal Pod template does.
 For instance, you are able to set Pod affinity, so that the PreBackup Pods are started on a specific node.
-That will allow you to get access to data that's RWO and then trigger backups for them via a backup command.
 
 [source,yaml]
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