Re: F2FS On USB Sticks?

On 2025-03-28 22:18, Lawrence D'Oliveiro wrote:

On Fri, 28 Mar 2025 14:49:02 +0100, Carlos E.R. wrote:
 

sticks and cards do not have wear levelling.

 Then they would benefit from using a filesystem format that integrates
wear-levelling in its storage-allocation algorithms, like the
aforementioned F2FS or NilFS2.

Certainly.
exFAT is one.
«exFAT (Extensible File Allocation Table) is a file system optimized for flash memory such as USB flash drives and SD cards,»
«exFAT has been adopted by the SD Association as the default file system for SDXC and SDUC cards larger than 32 GB.»
«Linux has support for exFAT via FUSE since 2009.[4] In 2013, Samsung Electronics published a Linux driver for exFAT under GPL.[32] On 28 August 2019, Microsoft published the exFAT specification[8] and released the patent to the Open Invention Network members.[33] The Linux kernel introduced native exFAT support with the 5.4 release in November 2019.[34]»
(<https://en.wikipedia.org/wiki/ExFAT>)
*Flash optimizations*
exFAT contains a few features that, according to Microsoft, makes it flash-friendly:
    * Boundary alignment for filesystem structures. The offsets for the FAT and the cluster heap is adjustable at format time, so that writes to these areas will happen in as few flash blocks as possible.
    * An "OEM parameters" field can be used to record features such as block size of the underlying storage. One single type for flash storage is pre-defined.[41]
    * The lack of a journal, so that less data is written. (Although FAT32 also lacks a journal.)
The first feature requires support from the formatting software. Compliant implementations will follow existing offsets. The OEM parameter may be ignored. Implementations may also use TRIM to reduce wear.
--
Cheers, Carlos.