PVs role as RWX and RWO?

Products

• DX Operational Intelligence
• DX Operational Observability

Issue/Introduction

For a new installation using DX O2 version 26.1, which access modes are supported on the Persistent Volumes? RWX or RWO? Or both?

Environment

DX O2 26.1 onpremise.

Resolution

The information regarding the explicit split between ReadWriteOnce (RWO) and ReadWriteMany (RWX)

When you unpack the on-premise installation package, the mapping is defined inside the dxi-generate-pvs.sh utility script.ff
When you execute that script, the logic embedded in it generates Persistent Volumes (PVs) that separate the stateful components (like Elasticsearch and PostgreSQL) into RWO block requirements, while placing configuration and logging bundles into RWX requirements.

All PVs and PVCs created in 26.1 (through installer+charts or using dxi-generate-pvs script) are using "ReadWriteMany" (RWX) access modes. So if creating PVs manually, set access modes to RWX for all PVs. Trying to change any of them to RWO will require customizations in charts and can easily lead to issues during installation/upgrade.

Regarding performance, we have IO requirements in documentation. If requirements are not met, DXO2 can face performance issues. If needed, elasticsearch/kafka PVs can be configured to use separate NFS servers.