Seems OpenZFS has a problem which, under rare conditions, can turn parts of your data into rubbish <https://www.theregister.com/2023/11/27/openzfs_2_2_0_data_corruption/>. Initially it was thought this bug was introduced in version 2.2.0, but now there is some indication that it goes back much earlier. It certainly seems difficult to reproduce, and at least one commenter on the article is saying not to worry about it, it’s not going to affect most “traditional” users (whatever that means). It seems the issue does date back to after Oracle closed the source on the original ZFS project and made it proprietary again. Open-source ZFS has long been a controversial issue. Linus Torvalds is not impressed with its performance, for example <https://list.waikato.ac.nz/archives/list/wlug(a)list.waikato.ac.nz/thread/CIWXJP57X2HOGUIG56DAHFVPLARI5XJT/>. Also, many have said that the licence it uses, the CDDL, is deliberately designed to be incompatible with the GPL used by the Linux kernel and many other projects. Ubuntu seem to disagree, and are happy to include OpenZFS with their Linux distro. Interestingly, Oracle also offer a Linux distro. And they have never offered ZFS with that, even though there is clearly demand for such a feature. Some interpret this as a tacit admission that the licence _is_ indeed GPL-incompatible. Because if Oracle bundled CDDL-licensed software with that made available under the GPL, then under the terms of the latter, they also give permission to anybody else to do the same. The implication is, they don’t want to do that.