Enterprise Storage OS
Enterprise Storage OS, also known as ESOS, is a Linux distribution that serves as a block-level storage server in a storage area network. ESOS is composed of open-source software projects that are required for a Linux distribution and several proprietary build and install time options. The SCST project is the core component of ESOS; it provides the back-end storage functionality.
Platform
ESOS is a niche Linux distribution. ESOS is intended to run on a USB flash drive, or some other type of removable media such as Secure Digital, CompactFlash, etc. ESOS is a memory resident operating system: At boot, a tmpfs file system is initialized as the root file system and the USB flash drive image is copied onto this file system. Configuration files and logs are periodically written to a USB flash drive or by user intervention when configuration changes occur.Interface
ESOS utilizes a text-based user interface for system management, network configuration, and storage provisioning functions. The TUI used in ESOS is written in C; the ncurses and CDK libraries are used.Front-end connectivity
ESOS supports connectivity on several different front-end storage area network technologies. These core functions are supported by SCST and third-party target drivers that vendors have developed for SCST:- Fibre Channel: QLogic HBAs are natively supported, and Emulex OneConnect FC HBAs can be supported by a build time option
- InfiniBand: Mellanox, QLogic, and Chelsio IB HCAs, among others, are supported
- Fibre Channel over Ethernet : A software target implementation supports NICs with DCB/DCBX capabilities, or build time options exist for supporting Emulex OneConnect FCoE CNAs and Chelsio Uwire FCoE CNAs.
- iSCSI: Will work over any IP communication method supported by ESOS.
Back-end storage
Open-source software projects and commodity computing server hardware are used on the back-end side to provide the underlying storage utilized by the front-end target interfaces:- Btrfs, XFS, and ext4 are all supported file systems for virtual disk files used with the "vdisk_fileio" device handler.
- Popular, modern hardware RAID controllers from LSI, Adaptec, HP, and Areca are also supported in ESOS, including install-time CLI tool integration for these adapters.
- Clustering and high-availability support is made possible by the Pacemaker and Corosync cluster software stack.
- DRBD is fully supported to facilitate replication between ESOS storage servers, and/or to create redundant ESOS storage server clusters.
- Virtual Tape Library support by the mhVTL project.
- Three SSD caching solutions: EnhanceIO, bcache, and dm-cache.
- Other block storage functions include the automated tiered storage via the BTIER project and Ceph RBD mapping.