Stratis Is Red Hat's Plan For Next-Gen Linux Storage Without Btrfs

[andrebrait]

*resisting the urge of posting xkcd: standards*

But really, it's quite hard to get companies to join efforts in the open source community, isn't it?

I really love Linux and open source software but damn... The duplication of effort is strong...

[dragon321]

what's the problem of ext4?

ext4 lacks many "modern" and advanced features like builtin compression, encryption, RAID, deduplication and more. Even it maintainer (Theodore Ts'o) said that btrfs is future for Linux storage.

[onicsis]

what's the problem of ext4?

From https://arstechnica.com/information-...n-filesystems/ Bitrot and atomic COWs: Inside “next-gen” filesystems

Generation 0: No system at all. There was just an arbitrary stream of data. Think punchcards, data on audiocassette, Atari 2600 ROM carts.

Generation 1: Early random access. Here, there are multiple named files on one device with no folders or other metadata. Think Apple ][ DOS (but not ProDOS!) as one example.

Generation 2: Early organization (aka folders). When devices became capable of holding hundreds of files, better organization became necessary. We're referring to TRS-DOS, Apple //c ProDOS, MS-DOS FAT/FAT32, etc.

Generation 3: Metadata—ownership, permissions, etc. As the user count on machines grew higher, the ability to restrict and control access became necessary. This includes AT&T UNIX, Netware, early NTFS, etc.

Generation 4: Journaling! This is the killer feature defining all current, modern filesystems—ext4, modern NTFS, UFS2, you name it. Journaling keeps the filesystem from becoming inconsistent in the event of a crash, making it much less likely that you'll lose data, or even an entire disk, when the power goes off or the kernel crashes.

---

ZFS—eldest of the next generation

• Atomic COW snapshots
• Per-block checksumming
• Self-healing redundant arrays
• Volume management
• Far-future scalability
• Asynchronous incremental replication

---

Features unique to btrfs

• File-level cloning
• Online balancing
• NODATACOW
• File-level/Directory-level compression

[Steffo]

I don't know... This seems just a tool set. Can it be as powerful like a full-featured next generation file system?

[duby229]

Meanwhile 8 years later..... Btrfs is still slow as hell and buggy... If RH can pull this off in just 2 years, Fantastic.

[duby229]

I don't know... This seems just a tool set. Can it be as powerful like a full-featured next generation file system?

I hate it to say it, I know it's gonna get some FUD, but..... Unix Philosophy FTW!

[Steffo]

I hate it to say it, I know it's gonna get some FUD, but..... Unix Philosophy FTW!

My experience is: If you want maximum performance and maximum flexibility and less code, then tightly integrated features are the way to go, otherwise you'll have much abstraction and redundant code.

[duby229]

My experience is: If you want maximum performance and maximum flexibility and less code, then tightly integrated features are the way to go, otherwise you'll have much abstraction and redundant code.

We'll have to wait and see if that is the case in this project. It usually isn't. EDIT: What is truly redundant is attempting to develop a system with highly integrated subsystems, when they are too integrated nobody else can use them and have to develop their own anyways. Which is often hard to do because entrenchment.

[Michael_S]

ext4 is a journaling filesystem.

btrfs is a journaling filesystem that also has these features not in ext4:
1. copy-on-write
2. checksums on data and metadata to detect file and filesystem corruption. This feature is very handy if you have a lot of data, but calculating and storing checksums every time you write data and calculating checksums again every time you read data does make it slower than filesystems without the feature. Ext4 does checksums for metadata but not on file data.
3. Online filesystem growth and shrinking. I know XFS has online filesystem growth, I've never tried XFS filesystem shrinking.
4. Transparent compression.
5. Snapshots.
6. Subvolumes. You can mount a subvolume without mounting the parent volume, snapshot individual subvolumes, and designate different replication levels for subvolumes than for the parent volume (RAID 1 or RAID 10 or similar).

We just had a long discussion or debate about btrfs on a previous post. I've got it on about seven drives, and I've been using it since 2013 and never had a problem. The speed is fine too.

[oleid]

... and in 10 years the Stratis developers will still be trying to beat down all those pesky RAID bugs, etc.

It would seem stratis won't do anything itself; it's merely a deamon managing LVM and maybe mdraid. Hence, it won't have any RAID bugs.