I've never heard of a .git folder that spanned multiple filesystems. It sounds like we are now conflating the git workspace with everything else in the product.
There are system requirements that a customer would be expected to adhere to if they wanted a valid enterprise support contract with one of these vendors.
I think GP's point is that the filesystems used by someone self-hosting gitlab may not be the same as what gitlab themselves are using.
File systems can be weird. Sometimes the OS can be weird and fsync type calls may not do what you expect. At least at one point MacOS fsync didn't behave the same way as Linux (i.e. Linux should ensure the write is truly done and not just in cache so long as the drive isn't lying). [0]
> There are system requirements that a customer would be expected to adhere to if they wanted a valid enterprise support contract with one of these vendors.
Gitlab has a community edition. Not handling data well would be bad for their public image.
I can't reply to the other reply for some reason, but what they said is indeed what I meant. gitlab.com might be running their Gitaly servers on btrfs or zfs or lvm volumes or whatever, but other customers may be using ext2. Gitlab the company could require customers to only run Gitaly on a specific filesystem, but up to now, they never have, it would be pretty shitty to suddenly change their minds after a decade plus of establishing one expectation, and whoever the developer is who submitted the patch to upstream Git and got a technical blog post out of it has absolutely no power to dictate contract terms to enterprise customers personally and instead did what is actually in their power to do.
There are system requirements that a customer would be expected to adhere to if they wanted a valid enterprise support contract with one of these vendors.