October 31 - November 1 - Co-Located Events
October 28-30 - Conference
Lyon Convention Centre - Lyon, France
More information for Open Source Summit + Embedded Linux Conference Europe 2019
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Wednesday, October 30 • 11:30 - 12:05
File System Support for Zoned Block Devices - Naohiro Aota & Damien Le Moal, Western Digital

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Zoned block device (ZBD) support has been introduced in Linux with kernel
version 4.10. ZBDs have different write constraints than regular block devices.
A ZBD is divided into several zones and each zone must be written sequentially.

The main type of ZBD currently available is SMR HDDs. The NVMe Zoned NameSpace
proposal is also being drafted to add a zone abstraction to the NVMe specifications.

Natively supporting ZBDs in a filesystem is not a trivial change. Some
filesystems must rely on special block layer drivers to ensure sequential writes
(e.g. ext4 and the dm-zoned device mappers). Filesystems using a copy-on-write
design are better candidates for native ZBD support. Examples are F2FS and btrfs.

This talk discusses the principles of ZBD native support in filesystems. Support
in F2FS is discussed and the approach taken with btrfs is next presented. This
is followed with a performance comparison between filesystems with native ZBD
support and regular ones using dm-zoned.


Naohiro Aota

Principal Engineer, Western Digital
Naohiro Aota is working at the System Software Group within Western Digital Research. He is working on zoned block device support for file systems like btrfs. He presented the on-going btrfs work at LSFMM 2019.
avatar for Damien Le Moal

Damien Le Moal

Distinguished Engineer, Western Digital
Damien Le Moal manages the System Software Group within Western Digital Research. Damien is a regular contributor to Linux kernel block I/O stack and file system support for the ZBC and ZAC standards (zoned block devices) and is a maintainer of the kernel dm-zoned device mapper and... Read More →

Wednesday October 30, 2019 11:30 - 12:05 CET
Lumiere Auditortium
  Linux Systems
  • Session Slides Included Yes