spdk/spdk v16.08

v16.08: iSCSI target, NVMe over Fabrics maturity

on GitHub

This release adds a userspace iSCSI target. The iSCSI target is capable of exporting
NVMe devices over a network using the iSCSI protocol. The application is located
in app/iscsi_tgt and a documented configuration file can be found at etc/spdk/spdk.conf.in.

This release also significantly improves the existing NVMe over Fabrics target.

• The configuration file format was changed, which will require updates to
  any existing nvmf.conf files (see etc/spdk/nvmf.conf.in):
  • SubsystemGroup was renamed to Subsystem.
  • AuthFile was removed (it was unimplemented).
  • nvmf_tgt was updated to correctly recognize NQN (NVMe Qualified Names)
    when naming subsystems. The default node name was changed to reflect this;
    it is now "nqn.2016-06.io.spdk".
  • Port and Host sections were merged into the Subsystem section
  • Global options to control max queue depth, number of queues, max I/O
    size, and max in-capsule data size were added.
  • The Nvme section was removed. Now a list of devices is specified by
    bus/device/function directly in the Subsystem section.
  • Subsystems now have a Mode, which can be Direct or Virtual. This is an attempt
    to future-proof the interface, so the only mode supported by this release
    is "Direct".
• Many bug fixes and cleanups were applied to the nvmf_tgt app and library.
• The target now supports discovery.

This release also adds one new feature and provides some better examples and tools
for the NVMe driver.

• The Weighted Round Robin arbitration method is now supported. This allows
  the user to specify different priorities on a per-I/O-queue basis. To
  enable WRR, set the arb_mechanism field during spdk_nvme_probe().
• A simplified "Hello World" example was added to show the proper way to use
  the NVMe library API; see examples/nvme/hello_world/hello_world.c.
• A test for measuring software overhead was added. See test/lib/nvme/overhead.