Hacking a SUSE MLS 7.9 Cluster by roseswe

Description

SUSE MLS (Multi-Linux Support) - A subscription where SUSE provides technical support and updates for Red Hat Enterprise Linux (RHEL) and CentOS servers

The most significant operational difference between SUSE MLS 7 and the standard SUSE Linux Enterprise Server High Availability Extension (SLES HAE) lies in the administrative toolchain. While both distributions rely on the same underlying Pacemaker resource manager and Corosync messaging layer, MLS 7 preserves the native Red Hat Enterprise Linux 7 user space. Consequently, MLS 7 administrators must utilize the Pacemaker Configuration System (pcs), a monolithic and imperative tool. The pcs utility abstracts the entire stack, controlling Corosync networking, cluster bootstrapping, and resource management through single-line commands that automatically generate the necessary configuration files. In contrast, SLES HAE employs the Cluster Resource Management Shell (crmsh). The crm utility operates as a declarative shell that focuses primarily on the Cluster Information Base (CIB). Unlike the command-driven nature of pcs, crmsh allows administrators to enter a configuration context to define the desired state of the cluster using syntax that maps closely to the underlying XML structure. This makes SLES HAE more flexible for complex edits but requires a different syntax knowledge base compared to the rigid, command-execution workflow of MLS 7.

Scope is here MLS 7.9

Goals

• Get more familiar with MLS7.9 HA toolchain and Graphical User Interface and Daemons
• Create a two node MLS cluster with SBD
• Check different use cases
• Create a "SUSE Best Practices" presentation slide set suitable for Consulting Customers

Resources

• You need MLS7.9 (Qcow2) installed + subscription
• KVM server with 2 KVMs, 2 SBD
• RHEL7 and HA skills