Overview¶

HwameiStor provides two kinds of local data volumes: LVM and Disk.

As a part of HwameiStor, the local disk is responsible for providing LVM local data volumes, including highly available LVM data volumes and non-highly available LVM data volumes.

Non-highly available LVM local data volumes are suitable for the following cases and applications:

A database with high availability features, such as MongoDB
Message middleware with high availability features, such as Kafka, RabbitMQ
A key-value store with high availability features, such as Redis
Other applications with high availability features

Highly available LVM local data volume, suitable for the following cases and applications:

Database, such as MySQL, PostgreSQL
Other applications that require high data availability

Hot backup mechanism¶

Single node hot backup¶

Raid 5 guarantee, can tolerate 1 set of disk failure.

Control flow and data flow are independent of each other to ensure the stability of data access.

Cross-node hot backup¶

Raid 5 + primary and backup copy protection.

The HA private network logical interface dce-storage is planned to synchronize storage traffic between nodes. Synchronously replicate data across nodes to ensure hot backup of data.

Data rebalancing¶

Balanced placement of data in the cluster is achieved through data volume migration technology. Move data online to nodes with more headroom.

Data volume type change¶

In order to support some special cases, single-copy data volumes are allowed to be changed to multiple copies, and cross-node hot backup is supported.