Did Sun/Oracle ever reveal what the magic was behind their ZFS ndmp implementation?

I'm just wondering if there was ever a ZFS native "stream to tape" format that was worth doing. Obviously you can zfs send incremental backups to a file, with a lot of manual bookkeeping, but it seems like half the appeal of the storage appliance was that you got that feature turnkey

zfs send, if anything, seems like a good way around the non-linear, "let's use tar" solution before the advent of LTFS. You just skip the middleman. But then you need something that bookends the replication streams

Was this the late 2000s era ndmp stuff or something else?

yes

I'm not sure if dap is here, but he'd know.

evidently it was a netapp specification? Heh, that probably didn't help the lawsuit

He did all the integration of the ndmp bits with the fishworks box.

it seems like it could be simple in principle, there's nothing to really prevent you from writing the linear stream of bytes out of ZFS send to tape, but there'd need to be some sort of envelope to make the reader aware of replication stream starts. I'm surprised there's nothing out there that attempts to do things this way (I mean other than what I think is the proprietary stuff owned by Oracle now)

The obvious tradeoff being that you can't just pull a single file from a tape, of course. Seems like a perfect mechanism for full backups, though

you mean beyond the ndmp server in illumos?

jbk: "The Oracle ZFS Storage Appliance has implemented a proprietary NDMP format which

enables the backup application to store block-level data to tape. "

sorry, PDF wrapped that line. oracle.com/technetwork/server-stora…tation/ndmp-implem-0615-2586112.pdf

I'm referring the NDMP extension that supposedly has some ZFS integration. Maybe this is just zfs send with an envelope and some extra steps?

it's a bit weird to me that this is referred to as proprietary, stayed proprietary, and nothing tried to RE it or emulate it. Was it any good? Seems like it could have been a good solution for incremental tape backup, with the obvious restore time tradeoff

working in sd.c is like trying to find a needle in nebraska

(a single haystack would be too small :P)