Sheepdog: Distributed Storage System for Virtual Machines

Technological fields
Information Sharing Platform Technologies
  • Virtualization
  • Storage
Laboratory organization
NTT Cyber Space Laboratories

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Sheepdog is a distributed storage system for virtual machines based on Linux*1 QEMU/KVM*2. It runs on multiple commodity servers and provides highly available and variously sized volumes to virtual machines. Sheepdog is an autonomous system; new servers join automatically, and failed nodes are automatically removed. In addition, Sheepdog scales to hundreds of servers and has linear scalability.


  • Reliable system with no single point of failure
  • Autonomous and easily manageable system
  • Scalable to hundreds of servers in performance and capacity
  • Developed as open source software and merged into QEMU/KVM
  • Supported by many other management systems (e.g. OpenStack, libvirt)

Application scenarios

  • Infrastructure as a Service
  • Hosting service based on virtualization
  • Server consolidation of many servers
  • Online storage service
  • *1 Linux is a registered trademark of Linus Torvalds in the U.S. and other countries.
  • *2 KVM: Kernel-based Virtual Machine