很棒的經驗分享. 但這件事沒那麼神, 純粹是案主找的資料救援太遜了.
問AI: does zfs storage metadata backup?
AI 摘要:
Yes, ZFS automatically stores multiple, redundant copies of its metadata (specifically 2-4 copies, including uberblocks) on-disk to protect against single-disk corruption. This redundant metadata is inherent to the filesystem, storing block pointers, file permissions, and directory structures directly on the data drives to allow for auto-repair.

ZFS本身就有存2到4份的metadata備份, 在硬碟全沒事的情況下, 應該只要找到備份的metadata, 就能救回全部的資料.

如果連備份的metadata也全壞了, 只要以前曾做過snapshot, 也有得救.
問AI: does zfs keep old metadata?
AI 摘要
Yes, ZFS keeps old metadata as long as it is referenced by an immutable snapshot. Due to its copy-on-write (COW) nature, when data or metadata is modified, ZFS writes new data to a new block rather than overwriting the old, preserving the previous state until all snapshots referencing it are destroyed.

以上這些問AI得到的答案其實都是在Rddit或StackOverFlow論壇裡有人發表的文章, 不是什麼密而不宣的高超技術. 實在是案主找的資料救援真的太遜了, 即使不熟ZFS, 連去網路找答案都懶.