Notice: HSE versions 2.0 and later do not make use of mpool. As a result, mpool is no longer actively maintained.
Mpool is a Linux® loadable kernel module that implements an object storage device interface for SSDs and other solid-state storage. It provides a high-performance alternative to file systems or raw block devices for applications that can benefit from its simple object storage model and unique features.
Mpool is designed for
- Traditional block SSDs
- Emerging SSD interfaces, such as NVMe Zoned Namespaces (ZNS), which often expose controller or media behaviors that impose I/O constraints
- Persistent memory
Mpool insulates client applications from these storage device and media details.
Mpool currently supports traditional block SSDs only.
Mpool was originally developed for the HSE storage engine, but is made available as a separate project.
- Object storage model comprising immutable blocks (blobs) and appendable logs
- Objects can optionally be placed on multiple classes of solid-state storage
- Facilities to memory-map arbitrary collections of block objects into a linear address space
- Proactive management of block object data in the Linux page cache based on object-level usage metrics
- Simultaneously access block object data directly and memory-mapped with no performance penalty
- Management model and CLI similar to that of Linux LVM
- C API library that can be embedded in any application
The mpool Wiki contains all the information you need to get started with mpool.