I cover this a bit in the post. Today they are running something like Longhorn backed by Oxide storage. When we release our CSI plugin they can use that instead.

why longhorn and not mayastor? longhorn doesn't even have nvmeof that is not experimental

Could be whichever. Customers have expressed a desired for Longhorn given they were already using it so we started our testing there. Ultimately our CSI plugin will be the official Oxide path.

Why Mayastor and not (Rook-)Ceph?

Slow, buggy and resource hungry. Faster spdk-based engine rewrite has been on the way for like 7 years now

One cool feature of ceph is reed solomon erasure coding, myastor only does replication if storage efficiency is important

4+2 Erasure Coding has only half the storage overhead of 3x replication but the same fault tolerance

Also re spdk

https://muratkarslioglu.com/blog/io-uring-spdk-kernel-bypass...

RS and XOR EC are definitely useful features for an object store that's storing from like tens of petabytes to exabytes worth of data but for a remote block device with a typical size up to a couple dozen terabytes I'm not so sure. Thanks for the link I will check it out

Edit: skimmed it, classic AI "analysis" - totally ignores all the crap io_uring went through

Buggy hasn't been my experience and the overhead should get smaller as storage grows. In any case, you'd get extra features such as S3, which would otherwise require running another service