F2FS Low-Memory Mode, Atomic Write Improvements For Linux 6.0

[phoronix]

Phoronix: F2FS Low-Memory Mode, Atomic Write Improvements For Linux 6.0

The Flash Friendly File-System (F2FS) continues showing its a formidable file-system option for flash memory devices, especially SSDs and mobile hardware. With Linux 6.0 there are yet more improvements for this file-system driver...

https://www.phoronix.com/news/Linux-6.0-F2FS

[guglovich]

Does F2FS compress? I understand it only to reduce wear and tear, but the number of occupied blocks does not change. And even this compression is difficult to activate.

[skeevy420]

Does F2FS compress? I understand it only to reduce wear and tear, but the number of occupied blocks does not change. And even this compression is difficult to activate.

You understand it well enough. Users don't reap the benefits of the extra freed up space. The compression with F2FS is used to send less data over the bus and for smaller read/write operations. For end users wanting more space, there are better choices like BTRFS, ZFS, and BcacheFS or slightly better choices like Reiser4/5, JFS, and NTFS.

It's not that much more difficult to use than any other file system. It has the extra step of needing a flag passed to mkfs, but after that it's the same as any other Linux FS -- set the appropriate mount flags or with chattr. Ext4 needs the same extra steps for case sensitivity.

While it's a nice file system, F2FS really isn't something the average desktop or server user should be using. It's a file system for embedded and portable flash drives that don't need to be universal (exFat). IMHO, unless you're setting up an embedded device, phone, Pi, SBC, etc on an EMMC, SD, USB it really isn't a file system you probably need to be using.

[MorrisS.]

Is f2fs the best file system for SSDs?

[skeevy420]

Is f2fs the best file system for SSDs?

No. It's better with simpler drives like Flash and NAND. SSDs with more advanced write controllers/firmware are (should be) better off with general purpose file systems; preferably using file systems with LZ4 or Zstd-Fast compression to maximize read/write throughput. At SSD and NVMe speeds you need to use a compressor that operates at your drive speed and LZ4 and Zstd-Fast are usually the best choices for that.

[MorrisS.]

No. It's better with simpler drives like Flash and NAND. SSDs with more advanced write controllers/firmware are (should be) better off with general purpose file systems; preferably using file systems with LZ4 or Zstd-Fast compression to maximize read/write throughput. At SSD and NVMe speeds you need to use a compressor that operates at your drive speed and LZ4 and Zstd-Fast are usually the best choices for that.

So it should be used in Usb memory stick.

[skeevy420]

So it should be used in Usb memory stick.

For Linux-only environments it works great on USB. I've ran entire distributions off USB with F2FS and recommend it for that. It's basically made and developed to be Android's RootFS on a NAND and for MicroSD cards.

[Weasel]

No. It's better with simpler drives like Flash and NAND. SSDs with more advanced write controllers/firmware are (should be) better off with general purpose file systems

Reason?

Preferably using file systems with LZ4 or Zstd-Fast compression to maximize read/write throughput.

You can do that with F2FS as well.

[skeevy420]

Reason?

That's why it was made. From their own documentation:

WHAT IS Flash-Friendly File System (F2FS)?¶

NAND flash memory-based storage devices, such as SSD, eMMC, and SD cards, have been equipped on a variety systems ranging from mobile to server systems. Since they are known to have different characteristics from the conventional rotating disks, a file system, an upper layer to the storage device, should adapt to the changes from the sketch in the design level.

F2FS is a file system exploiting NAND flash memory-based storage devices, which is based on Log-structured File System (LFS). The design has been focused on addressing the fundamental issues in LFS, which are snowball effect of wandering tree and high cleaning overhead.

Since a NAND flash memory-based storage device shows different characteristic according to its internal geometry or flash memory management scheme, namely FTL, F2FS and its tools support various parameters not only for configuring on-disk layout, but also for selecting allocation and cleaning algorithms.

That said, a general purpose file system using the noop or none IO scheduler works just as well on SDDs. Anecdotally, most consumer-grade 2.5 SSD drives are designed with Windows or macOS with NTFS, exFat, HFS, and APFS in mind...general purpose file systems.

You can do that with F2FS as well.

Only for better throughput; you can't utilize the space it saves. Most every other file system can utilize the free space while achieving better throughput via compression.

[arun54321]

Is f2fs the best file system for SSDs?

Yes. don't listen to those guys who try to downplay f2fs. I am using it for 3 years and the performance is better than other filesystems.