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The Translucent File Service (1988) [pdf] (mcvoy.com)
27 points by jxub 7 months ago | hide | past | web | favorite | 9 comments

Neat! I didn't know the copy-on-write semantics for filesystems went back that far, the first I knew about was UnionFS[1][2], which features the same semantics in a larger package.

[1] http://unionfs.filesystems.org

[2] https://en.wikipedia.org/wiki/UnionFS

For others like me who aren't sure what copy-on-write is: https://stackoverflow.com/questions/628938/what-is-copy-on-w...

The BSD 4.4 log-structured file system is the earliest CoW FS that I know of, though the ideas really go back earlier to the database world. (There's a tremendous amount of duality between databases and filesystems, so much so that it's pretty shocking that they haven't quite merged. WinFS should not have failed.)

I think of ZFS as a direct descendant of the 4.4BSD LFS, though I don't know that it is so -- in fact, I suspect Bonwick et. al. did not take inspiration from 4.4BSD LFS, but came up with a filesystem that looks inspired by it.

> I didn't know the copy-on-write semantics for filesystems went back that far

WAFL [1] from NetApp was/is widely in use, utilising CoW, and possibly older than this paper (wasn't able to verify but I know its from '90s at least).

This paper might've been interesting for the legal dispute between Sun and NetApp. Got settled with Oracle in 2010 though.

[1] https://en.wikipedia.org/wiki/Write_Anywhere_File_Layout

TFS introduced copy-on-write in 1986 (with SunOS 3). This is probably the first such implementation. Not sure if there was anything comparable before that, meeting the same definition of layered and copy-on-write.

WAFL came a few years later - in development in the early '90s, reached production in 1994.

My bad, I read through the document but I misread it as 1998.

The 4.4BSD log-structured filesystem was the first CoW FS I'm aware of. The ideas go back earlier still to the DB world. There is a lot of prior art in this space.

NSE was an awesome development environment when it worked. Unfortunately, it often became corrupted and suffered a lot of down time. Just a touch too much cleverness for the systems at the time.

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