ovh · OvhValentin · Apr 23, 2025 · Apr 24, 2025 · Apr 29, 2025
diff --git a/pages/index.md b/pages/index.md
@@ -602,6 +602,7 @@
         + [Infrastructure](public-cloud-cross-functional-infrastructure)
             + [Comparison and resilience of Deployment Modes - Understanding 3-AZ / 1-AZ / Local Zones](public_cloud/public_cloud_cross_functional/deployment_modes_comparison_resilience_details)
             + [3-AZ resilience - Mechanisms and reference architectures](public_cloud/public_cloud_cross_functional/3az_ref_architecture)
+            + [Proper Usage and Limitations of Classic Multi-Attach Block Storage in 3AZ Regions](public_cloud/compute/classic_block_multi_az_limitations)
         + [Billing information](public-cloud-cross-functional-billing-information)
             + [How do Savings Plans work?](public_cloud/public_cloud_cross_functional/savings_plans)
             + [How to manage a Savings Plan](public_cloud/public_cloud_cross_functional/how_to_manage_savings_plan)
@@ -660,6 +661,7 @@
             + [Test disk speed](public_cloud/compute/test_disk_speed)
             + [Change your Block Storage volume type](public_cloud/compute/switch_volume_type)
             + [Transfer a volume backup from one datacentre to another](public_cloud/compute/transfer_volume_backup_from_one_datacentre_to_another)
+            + [Proper Usage and Limitations of Classic Multi-Attach Block Storage in 3AZ Regions](public_cloud/compute/classic_block_multi_az_limitations)
         + [Tutorials](public-cloud-compute-tutorials)
             + [How to create and use authentication keys for SSH connections to Public Cloud instances](public_cloud/compute/creating-ssh-keys-pci)
             + [How to configure additional SSH keys on an instance](public_cloud/compute/configuring_additional_ssh_keys)

diff --git a/pages/public_cloud/compute/classic_block_multi_az_limitations/guide.en-gb.md b/pages/public_cloud/compute/classic_block_multi_az_limitations/guide.en-gb.md
@@ -0,0 +1,53 @@
+---
+title: Proper Usage and Limitations of Classic Multi-Attach Block Storage in 3AZ Regions
+excerpt: 'Learn how to safely use Classic Multi-Attach Block Storage in 3AZ regions, understand its limitations, and avoid data corruption.'
+updated: 2025-04-28
+---
+
+## Introduction
+
+Classic Multi-Attach 3AZ is a regional multi-zone volume type, available exclusively in Public Cloud regions with three Availability Zones (3AZ). This volume type allows a single volume to be attached simultaneously to multiple instances within the same region, enabling increased resilience and high availability for critical applications.
+
+This feature is designed specifically for active/active or active/passive use cases, where multiple instances need coordinated access to shared data.
+
+To better understand the underlying architecture for multi-zone deployments using regional Block Storage, refer to the following [documentation](/pages/public_cloud/public_cloud_cross_functional/3az_ref_architecture#2az-with-regional-block-storage).
+
+> [!warning]
+>
+> It is the user's responsibility to ensure that a cluster-aware file system is used with Classic Multi-Attach volumes.
+>
+> Failure to do so can result in data corruption.
+> 
+> Use only file systems designed for shared access, such as GFS2 or OCFS2.
+>
+> Standard file systems (e.g., XFS, EXT4, NTFS) are not supported unless proper fencing mechanisms are in place.
+>
+
+## Usage
+
+Creating and attaching a Classic Multi-Attach volume follows the same process as described in [OVHcloud documentation on volume creation](/pages/public_cloud/compute/starting_with_managing_volumes_openstack_api). The key difference is that the volume type is "classic-multiattach", not just "classic".
+
+If the volume type is omitted during creation, OpenStack will default to "classic-multiattach" (similar to how "classic" is set by default in regular regions).
+
+In the OVHcloud Manager, simply select the classic volume available in the 3AZ region.
+
+![classic 3az block volume](images/create_volume_type.png){.thumbnail}
+
+##  Considerations
+
+When working with Classic Multi-Attach in 3AZ regions, the following points should be taken into account:
+
+- Classic 3AZ Multi-Attach volumes can be attached to up to 16 instances simultaneously within the same region.
+- The multi-attach feature is only available with this specific volume type and exclusively in 3AZ regions, such as the Paris region.
+- Using cluster-aware file systems is required, but may result in performance degradation depending on the workload and configuration.
+
+## Limitations
+
+Classic Multi-Attach volumes come with specific limitations that should be considered before deployment:
+
+- Volume retyping is not supported while the volume is in use — switching from a multiattach-capable type to a non-multiattach-capable type (or vice-versa) is not allowed.
+- Encryption is not available for multiattach-capable volumes.
+
+## Go further
+
+Join our [community of users](/links/community).
diff --git a/pages/public_cloud/compute/classic_block_multi_az_limitations/guide.fr-fr.md b/pages/public_cloud/compute/classic_block_multi_az_limitations/guide.fr-fr.md
@@ -0,0 +1,53 @@
+---
+title: Utilisation correcte et limitations du stockage Classic Multi-Attach dans les régions 3AZ
+excerpt: 'Découvrez comment utiliser en toute sécurité le stockage Classic Multi-Attach dans les régions 3AZ, comprendre ses limitations et éviter la corruption de données.'
+updated: 2025-04-28
+---
+
+## Introduction
+
+Classic Multi-Attach 3AZ est un type de volume régional multi-zone, disponible exclusivement dans les régions Public Cloud disposant de trois zones de disponibilité (3AZ). Il permet à un même volume d’être attaché simultanément à plusieurs instances situées dans la même région, offrant ainsi une meilleure résilience et une haute disponibilité pour les applications critiques.
+
+Cette fonctionnalité est conçue spécifiquement pour les cas d’usage en actif/actif ou actif/passif, où plusieurs instances doivent accéder de manière coordonnée à des données partagées.
+
+Pour mieux comprendre l’architecture sous-jacente des déploiements multi-zones utilisant le Block Storage régional, consultez la documentation dédiée.
+
+> [!warning]
+> 
+> Il est de la responsabilité de l’utilisateur de s’assurer qu’un système de fichiers compatible multi-attache ou clusterisé est utilisé avec les volumes Classic Multi-Attach.
+> 
+> Dans le cas contraire, cela peut entraîner une corruption des données.
+> 
+> Utilisez uniquement des systèmes de fichiers conçus pour l’accès partagé, tels que GFS2 ou OCFS2.
+> 
+> Les systèmes de fichiers classiques (ex. : XFS, EXT4, NTFS) ne sont pas compatibles sans mécanismes de protection spécifiques (fencing).
+> 
+
+## Usage
+
+La création et l'attachement d'un volume Classic Multi-Attach suivent le même processus que celui décrit dans la [documentation OVHcloud sur la création de volume](/pages/public_cloud/compute/starting_with_managing_volumes_openstack_api). La principale différence est que le type de volume est « classic-multiattach », et pas seulement « classic ».
+
+Si le type de volume est omis lors de la création, OpenStack utilisera par défaut « classic-multiattach » (similaire à la façon dont « classic » est défini par défaut dans les régions ordinaires).
+
+Dans OVHcloud Manager, il suffit de sélectionner le volume classique disponible dans la région 3AZ.
+
+![classic 3az block volume](images/create_volume_type.png){.thumbnail}
+
+##  Considerations
+
+Les points suivants doivent être pris en compte lors de l'utilisation de volume Classic Multi-Attach dans les régions 3AZ :
+
+- Les volumes Classic 3AZ Multi-Attach peuvent être attachés à un maximum de 16 instances simultanément dans la même région.
+- La fonctionnalité multi-attaches n'est disponible qu'avec ce type de volume spécifique et exclusivement dans les régions 3AZ, telles que la région parisienne.
+- L'utilisation de systèmes de fichiers compatibles avec les clusters est nécessaire, mais peut entraîner une dégradation des performances en fonction de la charge de travail et de la configuration.
+
+## Limitations
+
+Les volumes Classic Multi-attach sont assortis de limitations spécifiques qu'il convient de prendre en compte avant de les déployer :
+
+- La réécriture du volume n'est pas prise en charge lorsque le volume est en cours d'utilisation - le passage d'un type compatible avec l'attachement multiple à un type non compatible avec l'attachement multiple (ou vice-versa) n'est pas autorisé.
+- Le chiffrement n'est pas disponible pour les volumes Classic Multi-attach.
+
+## Aller plus loin 
+
+Échangez avec notre [communauté d'utilisateurs](/links/community).
diff --git a/..._cloud/compute/classic_block_multi_az_limitations/images/create_volume_type.png b/..._cloud/compute/classic_block_multi_az_limitations/images/create_volume_type.png
diff --git a/pages/public_cloud/compute/classic_block_multi_az_limitations/meta.yml b/pages/public_cloud/compute/classic_block_multi_az_limitations/meta.yml
@@ -0,0 +1,2 @@
+id: 986ab224-29f8-40d8-803e-9892cb2cf487
+full_slug: public-cloud-storage-classic-multi-attach-3az
diff --git a/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.de-de.md b/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.de-de.md
@@ -65,7 +65,7 @@ This section presents reference architectures for multi-AZ deployment, illustrat
 > When AZ-a is restored, the Control Plane gradually reintegrates the resources and instances concerned into the overall infrastructure. For zonal services (e.g. instances, High Speed Block), if data has been lost, recovery depends on the implementation of a backup strategy. In the absence of backup, some recent data may remain irrecoverable, except for services such as Block Storage Classic Multi-Zone or Object Storage, which have built-in resilience mechanisms.
 >
 
-/// details | **Deployment in 2-AZ with regional Block Storage**
+/// details | **Deployment in 2-AZ with regional Block Storage** <a name="2az-with-regional-block-storage"></a>
 
 ![2-az with regional Block storage](images/2az-with-regional-storage.png){.thumbnail}
 

diff --git a/...ublic_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.en-asia.md b/...ublic_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.en-asia.md
@@ -65,7 +65,7 @@ This section presents reference architectures for multi-AZ deployment, illustrat
 > When AZ-a is restored, the Control Plane gradually reintegrates the resources and instances concerned into the overall infrastructure. For zonal services (e.g. instances, High Speed Block), if data has been lost, recovery depends on the implementation of a backup strategy. In the absence of backup, some recent data may remain irrecoverable, except for services such as Block Storage Classic Multi-Zone or Object Storage, which have built-in resilience mechanisms.
 >
 
-/// details | **Deployment in 2-AZ with regional Block Storage**
+/// details | **Deployment in 2-AZ with regional Block Storage** <a name="2az-with-regional-block-storage"></a>
 
 ![2-az with regional Block storage](images/2az-with-regional-storage.png){.thumbnail}
 

diff --git a/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.en-au.md b/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.en-au.md
@@ -65,7 +65,7 @@ This section presents reference architectures for multi-AZ deployment, illustrat
 > When AZ-a is restored, the Control Plane gradually reintegrates the resources and instances concerned into the overall infrastructure. For zonal services (e.g. instances, High Speed Block), if data has been lost, recovery depends on the implementation of a backup strategy. In the absence of backup, some recent data may remain irrecoverable, except for services such as Block Storage Classic Multi-Zone or Object Storage, which have built-in resilience mechanisms.
 >
 
-/// details | **Deployment in 2-AZ with regional Block Storage**
+/// details | **Deployment in 2-AZ with regional Block Storage** <a name="2az-with-regional-block-storage"></a>
 
 ![2-az with regional Block storage](images/2az-with-regional-storage.png){.thumbnail}
 

diff --git a/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.en-ca.md b/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.en-ca.md
@@ -65,7 +65,7 @@ This section presents reference architectures for multi-AZ deployment, illustrat
 > When AZ-a is restored, the Control Plane gradually reintegrates the resources and instances concerned into the overall infrastructure. For zonal services (e.g. instances, High Speed Block), if data has been lost, recovery depends on the implementation of a backup strategy. In the absence of backup, some recent data may remain irrecoverable, except for services such as Block Storage Classic Multi-Zone or Object Storage, which have built-in resilience mechanisms.
 >
 
-/// details | **Deployment in 2-AZ with regional Block Storage**
+/// details | **Deployment in 2-AZ with regional Block Storage** <a name="2az-with-regional-block-storage"></a>
 
 ![2-az with regional Block storage](images/2az-with-regional-storage.png){.thumbnail}
 

diff --git a/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.en-gb.md b/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.en-gb.md
@@ -65,7 +65,7 @@ This section presents reference architectures for multi-AZ deployment, illustrat
 > When AZ-a is restored, the Control Plane gradually reintegrates the resources and instances concerned into the overall infrastructure. For zonal services (e.g. instances, High Speed Block), if data has been lost, recovery depends on the implementation of a backup strategy. In the absence of backup, some recent data may remain irrecoverable, except for services such as Block Storage Classic Multi-Zone or Object Storage, which have built-in resilience mechanisms.
 >
 
-/// details | **Deployment in 2-AZ with regional Block Storage**
+/// details | **Deployment in 2-AZ with regional Block Storage** <a name="2az-with-regional-block-storage"></a>
 
 ![2-az with regional Block storage](images/2az-with-regional-storage.png){.thumbnail}
 

diff --git a/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.en-ie.md b/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.en-ie.md
@@ -65,7 +65,7 @@ This section presents reference architectures for multi-AZ deployment, illustrat
 > When AZ-a is restored, the Control Plane gradually reintegrates the resources and instances concerned into the overall infrastructure. For zonal services (e.g. instances, High Speed Block), if data has been lost, recovery depends on the implementation of a backup strategy. In the absence of backup, some recent data may remain irrecoverable, except for services such as Block Storage Classic Multi-Zone or Object Storage, which have built-in resilience mechanisms.
 >
 
-/// details | **Deployment in 2-AZ with regional Block Storage**
+/// details | **Deployment in 2-AZ with regional Block Storage** <a name="2az-with-regional-block-storage"></a>
 
 ![2-az with regional Block storage](images/2az-with-regional-storage.png){.thumbnail}
 

diff --git a/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.en-sg.md b/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.en-sg.md
@@ -65,7 +65,7 @@ This section presents reference architectures for multi-AZ deployment, illustrat
 > When AZ-a is restored, the Control Plane gradually reintegrates the resources and instances concerned into the overall infrastructure. For zonal services (e.g. instances, High Speed Block), if data has been lost, recovery depends on the implementation of a backup strategy. In the absence of backup, some recent data may remain irrecoverable, except for services such as Block Storage Classic Multi-Zone or Object Storage, which have built-in resilience mechanisms.
 >
 
-/// details | **Deployment in 2-AZ with regional Block Storage**
+/// details | **Deployment in 2-AZ with regional Block Storage** <a name="2az-with-regional-block-storage"></a>
 
 ![2-az with regional Block storage](images/2az-with-regional-storage.png){.thumbnail}
 

diff --git a/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.en-us.md b/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.en-us.md
@@ -65,7 +65,7 @@ This section presents reference architectures for multi-AZ deployment, illustrat
 > When AZ-a is restored, the Control Plane gradually reintegrates the resources and instances concerned into the overall infrastructure. For zonal services (e.g. instances, High Speed Block), if data has been lost, recovery depends on the implementation of a backup strategy. In the absence of backup, some recent data may remain irrecoverable, except for services such as Block Storage Classic Multi-Zone or Object Storage, which have built-in resilience mechanisms.
 >
 
-/// details | **Deployment in 2-AZ with regional Block Storage**
+/// details | **Deployment in 2-AZ with regional Block Storage** <a name="2az-with-regional-block-storage"></a>
 
 ![2-az with regional Block storage](images/2az-with-regional-storage.png){.thumbnail}
 

diff --git a/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.es-es.md b/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.es-es.md
@@ -65,7 +65,7 @@ This section presents reference architectures for multi-AZ deployment, illustrat
 > When AZ-a is restored, the Control Plane gradually reintegrates the resources and instances concerned into the overall infrastructure. For zonal services (e.g. instances, High Speed Block), if data has been lost, recovery depends on the implementation of a backup strategy. In the absence of backup, some recent data may remain irrecoverable, except for services such as Block Storage Classic Multi-Zone or Object Storage, which have built-in resilience mechanisms.
 >
 
-/// details | **Deployment in 2-AZ with regional Block Storage**
+/// details | **Deployment in 2-AZ with regional Block Storage** <a name="2az-with-regional-block-storage"></a>
 
 ![2-az with regional Block storage](images/2az-with-regional-storage.png){.thumbnail}
 

diff --git a/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.es-us.md b/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.es-us.md
@@ -65,7 +65,7 @@ This section presents reference architectures for multi-AZ deployment, illustrat
 > When AZ-a is restored, the Control Plane gradually reintegrates the resources and instances concerned into the overall infrastructure. For zonal services (e.g. instances, High Speed Block), if data has been lost, recovery depends on the implementation of a backup strategy. In the absence of backup, some recent data may remain irrecoverable, except for services such as Block Storage Classic Multi-Zone or Object Storage, which have built-in resilience mechanisms.
 >
 
-/// details | **Deployment in 2-AZ with regional Block Storage**
+/// details | **Deployment in 2-AZ with regional Block Storage** <a name="2az-with-regional-block-storage"></a>
 
 ![2-az with regional Block storage](images/2az-with-regional-storage.png){.thumbnail}
 

diff --git a/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.fr-ca.md b/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.fr-ca.md
@@ -65,7 +65,7 @@ Cette section présente des architectures de référence pour un déploiement mu
 > Lorsque AZ-a est rétabli, le Control Plane réintègre progressivement les ressources et les instances concernées dans l'infrastructure globale. Pour les services zonaux (ex. instances, High Speed Block), si des données ont été perdues, la récupération dépend de la mise en œuvre d'une stratégie de backup. En l'absence de backup, certaines données récentes peuvent rester irrécupérables, sauf pour les services tels que Block Storage Classic Multi-Zone ou Object Storage, qui disposent de mécanismes de résilience intégrés.
 >
 
-/// details | **Déploiement en 2-AZ avec Block Storage régional**
+/// details | **Déploiement en 2-AZ avec Block Storage régional** <a name="2az-with-regional-block-storage"></a>
 
 ![2-az with regional Block storage](images/2az-with-regional-storage.png){.thumbnail}
 

diff --git a/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.fr-fr.md b/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.fr-fr.md
@@ -65,7 +65,7 @@ Cette section présente des architectures de référence pour un déploiement mu
 > Lorsque AZ-a est rétabli, le Control Plane réintègre progressivement les ressources et les instances concernées dans l'infrastructure globale. Pour les services zonaux (ex. instances, High Speed Block), si des données ont été perdues, la récupération dépend de la mise en œuvre d'une stratégie de backup. En l'absence de backup, certaines données récentes peuvent rester irrécupérables, sauf pour les services tels que Block Storage Classic Multi-Zone ou Object Storage, qui disposent de mécanismes de résilience intégrés.
 >
 
-/// details | **Déploiement en 2-AZ avec Block Storage régional**
+/// details | **Déploiement en 2-AZ avec Block Storage régional** <a name="2az-with-regional-block-storage"></a>
 
 ![2-az with regional Block storage](images/2az-with-regional-storage.png){.thumbnail}
 

diff --git a/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.it-it.md b/.../public_cloud/public_cloud_cross_functional/3az_ref_architecture/guide.it-it.md
@@ -65,7 +65,7 @@ This section presents reference architectures for multi-AZ deployment, illustrat
 > When AZ-a is restored, the Control Plane gradually reintegrates the resources and instances concerned into the overall infrastructure. For zonal services (e.g. instances, High Speed Block), if data has been lost, recovery depends on the implementation of a backup strategy. In the absence of backup, some recent data may remain irrecoverable, except for services such as Block Storage Classic Multi-Zone or Object Storage, which have built-in resilience mechanisms.
 >
 
-/// details | **Deployment in 2-AZ with regional Block Storage**
+/// details | **Deployment in 2-AZ with regional Block Storage** <a name="2az-with-regional-block-storage"></a>
 
 ![2-az with regional Block storage](images/2az-with-regional-storage.png){.thumbnail}
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		id: 986ab224-29f8-40d8-803e-9892cb2cf487
		full_slug: public-cloud-storage-classic-multi-attach-3az