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Comment by davidjfelix | Hacker News Reader

NBD = network block device. Hope I saved somebody a google.

Did nobody else learn to spell out an acronym the first time it's used?

I had heard of it, but I had to read "NBD" far too many times in that repo before I saw what it stood for.

I've always thought of it as common courtesy. It's super frustrating when you're reading something and thinking "great, but wtf are you actually going on about?"

no one knows how to write or how to use hypertext properly anymore and it drives me nuts.

Here I was thinking it's go "no big deal" server and client

"The Network Block Device is a Linux-originated lightweight block access protocol that allows one to export a block device to a client."

how does nbd compare to, say, iSCSI ?

beyond likely being simpler to understand/manage, i mean.

SCSI was a fairly wide-ranging protocol, supporting anything from hard disks to CD recorders to document scanners, and iSCSI could theoretically encapsulate all of that. SCSI also came with a lot of historical quirks, like 6/10/12/16 byte addressing, which were progressively added as devices got larger and requirements got more complex. As a result, implementing software to interact with iSCSI is a pain, because there's simply so much legacy weirdness to deal with.

NBD is much more narrowly focused. It exposes a single block device to the kernel, with a minimal set of commands focused on that use case (e.g. read, write, trim, prefetch, etc). It doesn't do as many things as iSCSI, but that's probably for the better.

It's much, much simpler than iSCSI, which is an advantage.

It's possibly more idiomatically Linux. But the Linux iSCSI initiator might (last I checked?) do a better job of utilizing the kernel block multiqueue interface than nbd, and thus might get higher I/O performance.

nbd is extremely simple to set up; iSCSI less so.

Thanks. My first thought is Next Business Day, then follow by 'Why this thing need server/client?'

My first thought was that it was a No Big Deal server akin to Python’s simple HTTP server

https://en.wikipedia.org/wiki/Network_block_device

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