Search results
Results from the WOW.Com Content Network
DRBD layers logical block devices (conventionally named /dev/drbdX, where X is the device minor number) over existing local block devices on participating cluster nodes. Writes to the primary node are transferred to the lower-level block device and simultaneously propagated to the secondary node(s). The secondary node(s) then transfers data to ...
The most common size for an HA cluster is a two-node cluster, since that is the minimum required to provide redundancy, but many clusters consist of many more, sometimes dozens of nodes. The attached diagram is a good overview of a classic HA cluster, with the caveat that it does not make any mention of quorum/witness functionality (see above).
Data centre tiers are defined levels of resiliency and redundancy for IT facility infrastructure. They are widely used in the data center, ISP and cloud computing industries as part of the engineering design for high availability systems. The standard data center tiers are: [1] Tier I: no redundancy; Tier II: partial N+1 redundancy
High availability (HA) is a characteristic of a system that aims to ensure an agreed level of operational performance, usually uptime, for a higher than normal period. [ 1 ] There is now more dependence on these systems as a result of modernization.
Highly Available Storage (HAST) is a protocol and tool set for FreeBSD written by Pawel Jakub Dawidek, a core FreeBSD developer. HAST provides a block device to be synchronized between two servers for use as a file system. The two machines comprise a cluster, where each machine is a cluster node.
The failure of disk hardware or a given storage node in a cluster can create a single point of failure that can result in data loss or unavailability. Fault tolerance and high availability can be provided through data replication of one sort or another, so that data remains intact and available despite the failure of any single piece of equipment.
The Linux-HA (High-Availability Linux) project provides a high-availability solution for Linux, FreeBSD, OpenBSD, Solaris and Mac OS X which promotes reliability, availability, and serviceability (RAS). [1] The project's main software product is Heartbeat, a GPL-licensed portable cluster management program for high-availability clustering. Its ...
IBM PowerHA SystemMirror (formerly IBM PowerHA and HACMP) is IBM's solution for high-availability clusters on the AIX Unix and Linux for IBM System p platforms and stands for High Availability Cluster Multiprocessing. IBM's HACMP product was first shipped in 1991 and is now in its 20th release - PowerHA SystemMirror for AIX 7.1.