What is a DRBD in Linux?

DRBD (Distributed Replicated Block Device) is a Linux-based software component that facilitates the replacement of shared storage systems by networked mirroring. DRBD makes it possible to maintain consistency of data among multiple systems in a network. DRBD also ensures high availability (HA) for Linux applications.

What is DRBD protocol?

DRBD is a distributed replicated storage system for the Linux platform. It is implemented as a kernel driver, several userspace management applications, and some shell scripts.

Is DRBD open source?

DRBD or Distributed Replicated Block Device is an open source solution that provides a highly available, efficient, distributed storage system for the cluster environment.

Is DRBD synchronous?

DRBD supports both synchronous and asynchronous write operations, which will be further discussed below in relation to the three protocol setups.

What is quorum Linux?

A quorum disk is the storage type of cluster configurations. It acts like a database which holds the data related to clustered environment and duty of the quorum disk is to inform the cluster which node/nodes are to keep in ALIVE state. It allows concurrent access to it from all the other nodes to read/write data.

How do you use DRBD?

Step involved to install and Configure DRBD on RHEL7 / CentOS7

1. Download DRBD and Install the DRBD Packages.
2. Configuring DRBD.
3. Initialize the meta data storage on each nodes.
4. Starting and Enabling the DRBD Daemon.
5. Enable the DRBD Primary node.
6. Create and mount the Filesystem of DRBD device.
7. Testing the configurations.

What is Linstor?

LINSTOR is open-source software designed to manage block storage devices for large Linux server clusters. LINSTOR® is open-source software designed to manage block storage devices for large Linux server clusters.

What are the types of quorum?

Quorum Types

• Node Majority. This is the easiest quorum type to understand and is recommended for clusters with an odd number of nodes (3-nodes, 5-nodes, etc.).
• Node & Disk Majority.
• Node & File Share Majority.
• Legacy: Disk Only.

Is a quorum?

A quorum is the minimum number of members of a deliberative assembly (a body that uses parliamentary procedure, such as a legislature) necessary to conduct the business of that group.

How do I check my DRBD status?

You can view the status of the drbd application by running cat /proc/drbd from the command line of a cluster member. ds. disk state (State of the hard disks. The local disk state is always displayed first, the remote disk state last).

What is DRBD split brain?

Split-brain is an error state that occurs when the images of data on each IBM® Netezza® host are different. While DRBD does have automatic correction processes to resolve split-brain situations, the Netezza implementation disables the automatic correction.

What is Portworx?

Portworx is a software-defined storage platform built for containers and microservices. It abstracts multiple storage devices to expose a unified, overlay storage layer to cloud native applications.

How does DRBD work and how does the kernel work?

DRBD is split into two independent pieces: a kernel module that implements the DRBD behaviours and a set of user-space administration applications used to manage the DRBD disks. The kernel module implements a driver for a virtual block device (which is replicated between a local disk and a remote disk across the network).

Where is DRBD located in the Linux stack?

DRBD’s core functionality is implemented by way of a Linux kernel module. Specifically, DRBD constitutes a driver for a virtual block device, so DRBD is situated right near the bottom of a system’s I/O stack.

Is it possible to add features to DRBD?

DRBD is, by definition and as mandated by the Linux kernel architecture, agnostic of the layers above it. Thus, it is impossible for DRBD to miraculously add features to upper layers that these do not possess. For example, DRBD cannot auto-detect file system corruption or add active-active clustering capability to file systems like ext3 or XFS.

What makes DRBD a good replication solution for Linux?

Because of this, DRBD is extremely flexible and versatile, which makes it a replication solution suitable for adding high availability to just about any application. DRBD is, by definition and as mandated by the Linux kernel architecture, agnostic of the layers above it.