Category Archives: Standards Meetings

Atomic Commands Part IV: Wrapping it Up

At the May T10 meeting in Vancouver BC, a revision of the atomic write proposal was brought in by Samsung, HP, and NetApp (SBC-4 SPC-5 Atomic writes and reads (14-043) [Martin, Ballard, Knight]) and was accepted by the committee. This provides for a single atomic write and associated information regarding atomic boundaries and granularities. It is unlikely that any vectored command will be proposed unless a strong champion arrives.

This is probably unlikely in the near term, given the unprecedented consolidation now occurring in the solid state storage industry. For example, LSI was acquired by Avago and then sold the SandForce organization to Seagate, while Sandisk acquired Fusion-io. It is more likely that the features that flash technologies can provide will become available through proprietary software stacks for the time being.

Perhaps the most interesting work around persistent memory is occurring in the SNIA Non Volatile Memory technical work group (NVMP). This group has been dealing with some of the changes required by software applications to accommodate using non-volatile memory as storage. Discussions around atomics and transactional operations are routine in this work group, and participation by industry leaders has been steadily growing, a good indication of interest in this technology. The first draft specification is available now, and works in continuing on dealing with further topics, including remote persistent memory and isolation.

T10 (SCSI) March 2014 Meeting


The March T10 meeting week was held in New Orleans, Louisiana this year. SOP-1, PQI-1, SBC-3, all closed public review with no comments. SPC-4 should go to public comment in May 2014.The atomic read and write proposals were overhauled after being rejected at the January plenary meeting, but all to no avail. Work on the initial draft of Zone Block Recording (ZBR) continues in force.

My full notes are here, the official T10 minutes for CAP are here, and the T10 minutes for the plenary sessions are here.

T10 (SCSI) January 2014 Meeting


I attended the INCITS T10 (SCSI) meeting on January 13 to 16 in a warm and sunny Orange County. The highlights of the meeting:

  • One of my perennial favorites, Atomic Writes and Reads (13-064r8) was passed in the CAP committee meeting with 11 yes and 3 no votes, but when it was reviewed in the plenary meeting, it failed to pass with 4 yes and 8 no votes. Back to the drawing board.
  • SPC-4 Letter ballot comment resolution (13-256r3) continued, with some 800 comments remaining to be resolved.
  • Work began in earnest on the Zoned Block Commands (ZBC 14-051r3) specification for SCSI zoned block devices, notably those employing shingled write.

 My complete notes for the meeting can be found here.