From d2f265d0228a6c5d6bb20eb7b553c11b40011863 Mon Sep 17 00:00:00 2001
From: Bala Harish <161304963+balaharish7@users.noreply.github.com>
Date: Mon, 20 Jan 2025 11:44:40 +0530
Subject: [PATCH 1/3] docs: added info. regarding nvme_core.multipath
Signed-off-by: Bala Harish <161304963+balaharish7@users.noreply.github.com>
---
.../replicated-pv-mayastor/advanced-operations/HA.md | 6 ++++++
.../replicated-pv-mayastor/rs-installation.md | 6 ++++++
2 files changed, 12 insertions(+)
diff --git a/docs/main/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/advanced-operations/HA.md b/docs/main/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/advanced-operations/HA.md
index 1ea1832d..5a7aa390 100644
--- a/docs/main/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/advanced-operations/HA.md
+++ b/docs/main/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/advanced-operations/HA.md
@@ -19,6 +19,12 @@ The HA node agent looks for I/O path failures from applications to their corresp
The volume's replica count must be higher than one for a new target to be established as part of switch-over.
:::
+To ensure optimal HA in Replicated PV Mayastor clusters:
+
+- Applications constrained to nodes with the `io-engine label` (`openebs.io/engine=mayastor`) will have the Nexus preferably placed on the same node where the application is scheduled. If the `io-engine` pod on a node is in a bad state, the Nexus may be placed on a different node.
+
+- The kernel parameter `nvme_core.multipath=Y` is mandatory to enable HA functionality. Without this configuration, failover to a new Nexus cannot be achieved effectively.
+
### How do I disable this feature?
:::info
diff --git a/docs/main/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/rs-installation.md b/docs/main/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/rs-installation.md
index 20040414..eeadd8c9 100644
--- a/docs/main/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/rs-installation.md
+++ b/docs/main/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/rs-installation.md
@@ -31,6 +31,12 @@ All worker nodes must satisfy the following requirements:
* **HugePage support**
* A minimum of **2GiB of** **2MiB-sized** pages
+* Enabling `nvme_core.multipath` is required for High Availability (HA) functionality in Replicated PV Mayastor. Ensure the kernel parameter `nvme_core.multipath=Y` is set during the installation. (This prerequisite is optional.)
+
+:::note
+If the application is constrained to nodes with the `io-engine label` (`openebs.io/engine=mayastor`), the Nexus is preferably placed on the same node where the application is scheduled.
+:::
+
### Network Requirements
* Ensure that the following ports are **not** in use on the node:
From fdb9a3aad7c89a5cc3a9e4a04dc912757c52af0f Mon Sep 17 00:00:00 2001
From: Bala Harish <161304963+balaharish7@users.noreply.github.com>
Date: Mon, 20 Jan 2025 15:18:10 +0530
Subject: [PATCH 2/3] docs: added info. regarding nvme_core.multipath
Signed-off-by: Bala Harish <161304963+balaharish7@users.noreply.github.com>
---
.../replicated-pv-mayastor/advanced-operations/HA.md | 6 ++++++
.../replicated-pv-mayastor/rs-installation.md | 6 ++++++
2 files changed, 12 insertions(+)
diff --git a/docs/versioned_docs/version-4.1.x/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/advanced-operations/HA.md b/docs/versioned_docs/version-4.1.x/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/advanced-operations/HA.md
index 1ea1832d..5a7aa390 100644
--- a/docs/versioned_docs/version-4.1.x/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/advanced-operations/HA.md
+++ b/docs/versioned_docs/version-4.1.x/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/advanced-operations/HA.md
@@ -19,6 +19,12 @@ The HA node agent looks for I/O path failures from applications to their corresp
The volume's replica count must be higher than one for a new target to be established as part of switch-over.
:::
+To ensure optimal HA in Replicated PV Mayastor clusters:
+
+- Applications constrained to nodes with the `io-engine label` (`openebs.io/engine=mayastor`) will have the Nexus preferably placed on the same node where the application is scheduled. If the `io-engine` pod on a node is in a bad state, the Nexus may be placed on a different node.
+
+- The kernel parameter `nvme_core.multipath=Y` is mandatory to enable HA functionality. Without this configuration, failover to a new Nexus cannot be achieved effectively.
+
### How do I disable this feature?
:::info
diff --git a/docs/versioned_docs/version-4.1.x/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/rs-installation.md b/docs/versioned_docs/version-4.1.x/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/rs-installation.md
index 1901eb15..1c820a48 100644
--- a/docs/versioned_docs/version-4.1.x/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/rs-installation.md
+++ b/docs/versioned_docs/version-4.1.x/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/rs-installation.md
@@ -31,6 +31,12 @@ All worker nodes must satisfy the following requirements:
* **HugePage support**
* A minimum of **2GiB of** **2MiB-sized** pages
+* Enabling `nvme_core.multipath` is required for High Availability (HA) functionality in Replicated PV Mayastor. Ensure the kernel parameter `nvme_core.multipath=Y` is set during the installation. (This prerequisite is optional.)
+
+:::note
+If the application is constrained to nodes with the `io-engine label` (`openebs.io/engine=mayastor`), the Nexus is preferably placed on the same node where the application is scheduled.
+:::
+
### Network Requirements
* Ensure that the following ports are **not** in use on the node:
From 45cff67678bfb7a84519614e0c8b353d26c1de20 Mon Sep 17 00:00:00 2001
From: Bala Harish <161304963+balaharish7@users.noreply.github.com>
Date: Mon, 20 Jan 2025 15:21:33 +0530
Subject: [PATCH 3/3] docs: mofified the docs as per the comments
Signed-off-by: Bala Harish <161304963+balaharish7@users.noreply.github.com>
---
.../replicated-pv-mayastor/advanced-operations/HA.md | 2 +-
.../replicated-pv-mayastor/rs-installation.md | 2 +-
.../replicated-pv-mayastor/advanced-operations/HA.md | 2 +-
.../replicated-pv-mayastor/rs-installation.md | 2 +-
4 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/docs/main/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/advanced-operations/HA.md b/docs/main/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/advanced-operations/HA.md
index 5a7aa390..9ac22c28 100644
--- a/docs/main/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/advanced-operations/HA.md
+++ b/docs/main/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/advanced-operations/HA.md
@@ -23,7 +23,7 @@ To ensure optimal HA in Replicated PV Mayastor clusters:
- Applications constrained to nodes with the `io-engine label` (`openebs.io/engine=mayastor`) will have the Nexus preferably placed on the same node where the application is scheduled. If the `io-engine` pod on a node is in a bad state, the Nexus may be placed on a different node.
-- The kernel parameter `nvme_core.multipath=Y` is mandatory to enable HA functionality. Without this configuration, failover to a new Nexus cannot be achieved effectively.
+- The kernel parameter `nvme_core.multipath=Y` is mandatory to enable HA functionality. Without this configuration, volume target failover is not possible.
### How do I disable this feature?
diff --git a/docs/main/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/rs-installation.md b/docs/main/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/rs-installation.md
index eeadd8c9..514c7f95 100644
--- a/docs/main/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/rs-installation.md
+++ b/docs/main/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/rs-installation.md
@@ -34,7 +34,7 @@ All worker nodes must satisfy the following requirements:
* Enabling `nvme_core.multipath` is required for High Availability (HA) functionality in Replicated PV Mayastor. Ensure the kernel parameter `nvme_core.multipath=Y` is set during the installation. (This prerequisite is optional.)
:::note
-If the application is constrained to nodes with the `io-engine label` (`openebs.io/engine=mayastor`), the Nexus is preferably placed on the same node where the application is scheduled.
+If the application is scheduled to nodes with the `io-engine label` (`openebs.io/engine=mayastor`), the volume target is preferably placed on the same node where the application is scheduled.
:::
### Network Requirements
diff --git a/docs/versioned_docs/version-4.1.x/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/advanced-operations/HA.md b/docs/versioned_docs/version-4.1.x/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/advanced-operations/HA.md
index 5a7aa390..9ac22c28 100644
--- a/docs/versioned_docs/version-4.1.x/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/advanced-operations/HA.md
+++ b/docs/versioned_docs/version-4.1.x/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/advanced-operations/HA.md
@@ -23,7 +23,7 @@ To ensure optimal HA in Replicated PV Mayastor clusters:
- Applications constrained to nodes with the `io-engine label` (`openebs.io/engine=mayastor`) will have the Nexus preferably placed on the same node where the application is scheduled. If the `io-engine` pod on a node is in a bad state, the Nexus may be placed on a different node.
-- The kernel parameter `nvme_core.multipath=Y` is mandatory to enable HA functionality. Without this configuration, failover to a new Nexus cannot be achieved effectively.
+- The kernel parameter `nvme_core.multipath=Y` is mandatory to enable HA functionality. Without this configuration, volume target failover is not possible.
### How do I disable this feature?
diff --git a/docs/versioned_docs/version-4.1.x/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/rs-installation.md b/docs/versioned_docs/version-4.1.x/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/rs-installation.md
index 1c820a48..a464e0fc 100644
--- a/docs/versioned_docs/version-4.1.x/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/rs-installation.md
+++ b/docs/versioned_docs/version-4.1.x/user-guides/replicated-storage-user-guide/replicated-pv-mayastor/rs-installation.md
@@ -34,7 +34,7 @@ All worker nodes must satisfy the following requirements:
* Enabling `nvme_core.multipath` is required for High Availability (HA) functionality in Replicated PV Mayastor. Ensure the kernel parameter `nvme_core.multipath=Y` is set during the installation. (This prerequisite is optional.)
:::note
-If the application is constrained to nodes with the `io-engine label` (`openebs.io/engine=mayastor`), the Nexus is preferably placed on the same node where the application is scheduled.
+If the application is scheduled to nodes with the `io-engine label` (`openebs.io/engine=mayastor`), the volume target is preferably placed on the same node where the application is scheduled.
:::
### Network Requirements