Clustering

Heartbeat provides Cluster infrastructure communication and membership services. This enables clients to know about the presence, or disappearance, of peer processes on other machines and to easily exchange messages with them. In order to be useful to users, the Heartbeat daemon needs to be combined with a Cluster resource manager (CRM) which has the task of starting and stopping the services (IP addresses, web servers, etc.) that the Cluster will make available. We can offer consultancy, training and support in relation to your Heartbeat requirements.

GFS and GFS2 differ from distributed file systems because they allow all nodes to have direct concurrent access to the same shared block storage. In addition, GFS or GFS2 can also be used as a local file system.

GFS has no disconnected operating-mode, and no client or server roles. All nodes in a GFS Cluster function as peers. Using GFS in a Cluster requires hardware to allow access to the shared storage, and a lock manager to control access to the storage. The lock manager is a separate module and thus GFS and GFS2 can use the Distributed Lock Manager (DLM) for Cluster configurations and the "nolock" lock manager for local file systems.

GFS and GFS2 are free software, distributed under the terms of the GNU General Public License. We can offer consultancy and support in relation to your GFS/GF2 requirements.

DRBD (Distributed Replicated Block Device) is a distributed storage system for the GNU/Linux platform. It consists of a kernel module, several user-space management applications and shell scripts and is normally used on high availability Clusters. DRBD runs over a network.

It is free software released under the terms of the GNU General Public License version 2. We can offer consultancy and support in relation to your DRBD requirements.