ACSLS HA is a hardware and software configuration that provides dual-redundancy, automatic recovery and automatic failover recovery to ensure uninterrupted tape library control service if component or subsystem failures occur. This document explains the configuration, setup and testing procedures required to provide High Availability to ACSLS software.
Note:
ACSLS HA Linux supports ACSLS 8.5.1 or later.It is best to review the complete installation process before beginning the procedure. The process of installing a clustered application involves multiple steps requiring strict attention to detail. This procedure is normally undertaken by specialists in UNIX/LINUX system integration.
The configuration is a two-node system. It includes two complete subsystems (one active and one standby) with monitoring software capable of detecting serious system failures. It can switch control from the primary to the standby system for any non-recoverable subsystem failure. The configuration provides redundant power supplies, and redundant network and I/O interconnections that can recover subsystem communication failures instantly without the need for a general switch over.
The system leverages the monitor and failover features built in to ACSLS HA. The multipath features in the Linux operating system provide resilient library control operation with minimal downtime. Linux offers IP bonding to ensure uninterrupted network connectivity and multipaths to NFS disk I/O with RAID 1 to ensure uninterrupted access to system data. ACSLS HA monitors the health of system resources including the internal hardware and external I/O resources. It can also manage a system switch over if required.
The ACSLS HA agent monitors the ACSLS application, its database, its file system, and connectivity to StorageTek library resources, invoking the ACSLSHA failover service, if needed. In this redundant configuration, the ACSLS Library Control Server has a single logical host identity, which is always known within the framework and to the rest of the world. This identity is transferred automatically as needed between the nodes with minimal downtime during the transition.
Before embarking on the project, review the complete process of installing and configuring ACSLS HA as it is documented here. If desired, Advanced Customer Services from Oracle can be arranged to advise, to assist, or to handle the entire installation.
An ACSLS HA server configuration consists of two identical Linux server nodes sharing an external NFS file system. Any network interface cards installed in the servers must be identical. This is because during configuration ACSLS HA will utilize the same operating system device name on each server.
ACSLS HA supports all ACSLS clients that use the Automated Cartridge System Application Programming Interface (ACSAPI) network interface. A single network IP address is shared between the two server nodes, allowing ACSAPI clients to address ACSLS using a common virtual host ID.
ACSLS HA 8.5.1 can run on any system that meets the minimum hardware requirements for Linux 7.3, 7.6, or 7.8.Systems generally include four Ethernet ports on the motherboard. Additional network interface cards are required in order to accommodate a total of eight Ethernet ports per server. Best practice dictates that the two servers and the external ethernet cards are identical. The naming conventions used in this document for network ports, bond names and NFS assumes these best practices.
Any network file system server is valid provided that its NFS4 options are set according to the installation instructions in this guide. NFS version 4 must be utilized.
The ACSLS Installation Guide instructs you to create users and groups on the ACSLSA server. You must also create these users and groups on the NFS server.
You must reserve a total of seven IP addresses:
One Logical Host IP address
Two NFS IP addresses
Two Library IP addresses
Two Node Interconnect IP addresses
Ideally, library interfaces reside on different subnets and attach to separate Host Library Interface cards. Best practice dictates that the ethernet cards installed in both systems be identical.
ACSLS HA installation involves the following steps:
Install two Linux platform servers. Refer to the document, Installing Oracle Linux 7.6 Systems, available from the Oracle Technology Network library. The root file system on the internal disks must be protected with some form of RAID or other redundancy.
Configure the basic Linux system including the cabling for seven network interface ports on each of two nodes.
Define and configure the bonded IP addresses for the ”node to node” interconnect and NFS.
Configure the NFS file system on the NFS server and mount it from each node.
Download software packages ACSLS 8.5.1 and ACSLS HA 8.5.1.
Install and configure ACSLS 8.5.1 and patch update (if any) on both nodes.
Install and configure ACSLS HA 8.5.1 on both nodes.
Start ACSLS HA on both servers and test the Logical IP and client connections to ACSLS.