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Open source storage is data storage software that is developed in a public, collaborative manner under a license that permits the free use, distribution and modification of the source code.
The term open source storage may also be used to describe commercially supported versions of open source storage software and commercial storage products that use open source software as an underlying technology. Some storage vendors use open source code in their products and add functionality to make the open source technology easier to use or offer enterprise capabilities the open source storage does not have.
Some storage vendors have started open source projects to further the development of their proprietary commercial software. One prominent example is Dell EMC's CoprHD open source project based on its ViPR Controller software.
Open source storage isn't limited to one type of storage infrastructure. It can be used for a storage area network (SAN), network-attached storage (NAS) or object storage. Enterprise organizations have several options to obtain open source storage, including project sites, SourceForge.net and commercial vendors.
Examples of open source storage
Ceph. Distributed block, file and object storage that scales across clustered server nodes. Vendors offering commercially supported products based on Ceph include Canonical, Fujitsu, Red Hat and SUSE.
Gluster File System. Scalable network file system. Red Hat is the major vendor of a commercially supported version of GlusterFS.
Lustre. Parallel distributed file system designed for high-performance computing environments. Vendors offering products with commercial support based on Lustre include Cray, Dell EMC, Fujitsu, Hewlett Packard Enterprise (HPE), SGI and Seagate Technology.
OpenStack Block Storage service, known by its project name, Cinder. Software to create and centrally manage a service designed to present storage resources to users of OpenStack Nova compute instances. More than 100 Cinder block storage drivers are available to enable different back-end storage. The Ceph RADOS Block Device is the most popular Cinder driver in production use. The OpenStack community makes available the default logical volume manager for Linux. Major storage vendors with Cinder block storage drivers include Dell EMC, IBM, HPE, Hitachi Data Systems and NetApp.
OpenStack Shared File Systems service, known by its project name, Manila. Software designed to provide a set of services to manage shared file systems, such as NFS exports and CIFS shares, in cloud environments. Storage vendors with Manila drivers include Dell EMC, HPE, Hitachi Data Systems, IBM, NetApp and Red Hat. Manila also supports niche file system protocols such as Gluster, Hadoop Distributed File System, MapR-FS and Ceph Filesystem (Ceph FS).
OpenStack Object Storage service, known by its project name, Swift. Distributed object storage designed for large quantities of unstructured data. Vendors that support Swift include HPE, IBM, Oracle, Red Hat, SUSE SwiftStack and VMware.
OpenZFS. File system and logical volume manager based on the ZFS technology created by Sun Microsystems. Built-in enterprise storage features include replication, deduplication, compression, snapshots, clones and data protection. Vendors with commercial products based on OpenZFS include Cloudscaling, Datto, Delphix, Joyent, Nexenta, SoftNAS and Spectra Logic.
Examples of storage vendors that use open source software as an underlying technology include Dell EMC (Isilon), Nexenta, Nexsan, Nutanix and Scale Computing.
Pros and cons of open source storage
Advantages of open source storage include no upfront software cost, the ability to run on commodity hardware, and freely available source code that a developer can inspect, customize or tune to suit the specific needs of an organization. Any developer is free to join an open source storage project, participate in its development and submit suggestions for future improvements. Open source advocates claim the transparent, public development process and peer review promote high quality, reliability and security, and offers the potential for speedier innovation than proprietary software.
Open source storage has a number of potential disadvantages. The software can be complex and difficult to use, require trained staff to deploy and maintain, and suffer from driver interoperability issues. Tuning and maintaining open source storage can become a time-consuming and costly endeavor for an IT organization.
Many enterprises opt to purchase a tested and supported version of open source storage software from a commercial vendor to ease deployment, maintenance and troubleshooting problems. They generally select hardware from suppliers with whom the vendor has partnered or from a list of tested and certified options.