this has a nasty side-effect with NFS, at least <= version 3. ext4 immediately makes the file being unlinked invisible in the filesystem namespace, and then blocks while it does the work of deallocating the space.

the NFS client will issue the unlink() call, not hear anything back from the NFS server as it's blocking doing the unlink(), and then eventually time out and retry the operation. at which point the server immediately will return ENOENT as the is no visible file at that path.

the annoying thing is that this interaction leaks through into userland programs, and then to users, who see "no such file or directory" errors which cause great confusion. I've seen this multiple times in HPC environments.

I've found ext4 to be generally unsuitable to HPC environments due to the 16TB filesize limitation. So it is the wrong tool for the job anyways. xfs all the way!

and much worse when fragmented on raid5.