FS Design Around SMR: Seagate’s Journey and Reference System with EXT4

Library Content Type:
Publish Date: 
Tuesday, September 22, 2015
Event Name: 

SMR is a game changer drive technology, embraced by all major manufacturers. SMR changes fundamental assumptions of file system management. This long-help abandonment of Random-Writes now makes drives behave as sequential-access tape.

Seagate is leading the way in providing a standards compliant IO stack for use with the new drives. Using the new ZAC/ZBC commands to make and maintain a file system is essential for performant operation. Seagate is sharing lessons learned from modifying EXT4 for use with SMR. This effort is called the SMR Friendly File System (SMRFFS).

Learning Objectives

Forward-write only considerations for the block allocation scheme
Zones/BlockGroup/AllocationGroup alignment and use Superblock, and other required write-in-place management schemes