zfs VS snapper

> The only non-junk PCIe3 option that's even advertised here recently is the overpriced WD Red SN700.

Those WD drives seem to have some real issues, at least with ZFS and btrfs. :(

https://github.com/openzfs/zfs/discussions/14793

IMO the "next fs" is just zfs. They somewhat recently merged RAIDZ expansion feature https://github.com/openzfs/zfs/pull/12225 and make regular improvements. If no file system has what you need today, zfs will probably be the first one to have it "tomorrow," imo.

https://github.com/openzfs/zfs/issues/15526#issuecomment-181...

> zpool get all tank | grep bclone

> kc3000 bcloneused 442M

> kc3000 bclonesaved 1.42G

> kc3000 bcloneratio 4.30x

> My understanding is this: If the result is 0 for both bcloneused and bclonesaved then it's safe to say that you don't have silent corruption.

A couple years ago, I had an idea for convincing a filesystem to go faster using 2 compression steps instead of one. I couldn't see why it wouldn't work, and I also couldn't convince myself it should.

It seems to have worked out. [1]

[1] - https://github.com/openzfs/zfs/commit/f375b23c026aec00cc9527...

https://github.com/openzfs/zfs/issues/7631

This is a long-standing issue with zvols which affects overall system stability, and has no real solution as of yet.

TIL. Thank you! https://github.com/openzfs/zfs/pull/15022

Difference may be significant, yes https://github.com/openzfs/zfs/pull/14243

I left SUSE close to the end of 2021, and I had had to reinstall my work laptop twice that year alone. I consider that recent enough to call it current.

> df is not lying

To me, that reads as "df isn't lying because $EXCUSES."

I disagree. I don't care about excuses. I want a 100% accurate accounting of free space at all times via the standard xNix free-disk-space reporting command, and the same from the APIs that command uses so that applications can also get an accurate report of free space.

If a filesystem cannot report free space reliably and accurately, then that filesystem is IMHO broken. Excuses do not exonerate the FS, and having other FS-specific commands that can report free space do not exonerate it. The `df` command must work, or the FS is broken.

The primary point of Btrfs is that it is the only GPL snapshot-capable FS. The other stuff is gravy: it's a bonus. There are distros that use Btrfs that don't use snapshots, such as Fedora.

Some Btrfs advocates use this to claim that the problems are not problematic. If the filesystem is of interest on the basis of feature $FOO, then "product $BAR does not exhibit this problem" is not an endorsement or a refutation if $BAR does not use feature $FOO.

Btrfs RAID is broken in important ways, but that is not a deal-breaker because there are other perfectly good ways of obtaining that functionality using other parts of the Linux stack. If no feature or functionality is lost considering the OS and stack as a whole, then that isn't a problem. However, this remains serious and an issue.

Additional problems include:

• Poor integration into the overall industry-wide OS stack.

Examples:

- Existing commands do not work or give inconsistent results.

- Duplication of functionality (e.g. overlap with `mdraid`)

• Poor integration into specific vendors' OS stacks.

Examples:

- SUSE uses Btrfs heavily.

But SUSE's `zypper` package manager is not integrated with its `snapper` tool. Zypper doesn't include snapshot space used by Snapper in its space estimation.

Snapper is integrated with Btrfs; licence restrictions notwithstanding, I would be much reassured if Snapper supported other COW filesystems.

(This has been attempted but I don't think anything shipped -- https://github.com/openSUSE/snapper/issues/145 . I welcome correction on this!)

The transactional features of SUSE's MicroOS family of distros rely heavily on it. This lack of awareness of snapshot space utilization deeply worries me. I have raised this with SUSE management, but my concerns were dismissed. That worries me.

Red Hat removed Btrfs support from RHEL. As a result it has had to bodge transactional package management together by grafting Git-like functionality into OStree, then building two entirely new packaging systems around OStree, one for the OS itself and a different one for GUI-level packages. The latter is Flatpak, of course.

This strikes me as prime evidence that:

1. Btrfs isn't ready.

Very useful. One practical thing to add: enabling automatic snapshots (e.g. with https://github.com/openSUSE/snapper), ideally backing them up separately (e.g., with borg) might help recovery.

I like btrfs snapshots, e.g. with snapper (http://snapper.io/), but that needs a bit of setup (and is out of the box with some distros, e.g. opensuse).

Use snapper, it's very good and it can be integrated with grub so that you can boot into an snapshot (not sure you can do that with timeshift).

The other big difference, is that I would like to have "flat" hierarchy (at least within the nested distro-specific subvol) for my snapshots. Meaning that I do not like the nested structure of /.snapshots that snapper seems to assume by default and would prefer something like /fedora/snapshots/rootfs instead. It seems this is a somewhat popular request that has been opened for over 8 years... but since it hasn't been implemented in snapper itself, most people just use workarounds.

If, for some reason, anything goes wrong with your system, it is also trivial to return it to a working state, using snapper. This is preconfigured by default, no manual work required.

Are you sure you need a full on virtual machine, rather than a system snapshotting tool like Snapper or Timeshift?

I never said it did. Please read. It was meant to demonstrate that the health of the project is questionable, since after thatf ater that change was submitted, the official tests for the project is broken (see the current status on their github page https://github.com/openSUSE/snapper).

The amazing tooling: - YaST, the best configuration tool out there. I think its fair to say that nothing comes close to the number of things you can configure with Yast. - Open Build Service (OBS), a tool that automatically builds binaries for software and sets up repositories to add to your favorite package manager. Supports every major linux distro but intergrates especially well with the openSUSE software store, and OPI (openSUSE equivelant to something like paru or yay) to be like the AUR but (imo) better. - openQA, Automated testing for any package or operating system, making sure that even on leading edge software, you're still stable. - snapper, out of the box btrfs snapshots that make sure you can (almost) always boot into a useable system, even after a bumpy update.