Re: PostgreSQL's handling of fsync() errors is unsafe and risks data loss at least on XFS

On 10 April 2018 at 02:59, Craig Ringer <craig@2ndquadrant.com> wrote:

> Nitpick: In most cases the kernel reserves disk space immediately,
> before returning from write(). NFS seems to be the main exception
> here.

I'm kind of puzzled by this. Surely NFS servers store the data in the
filesystem using write(2) or the in-kernel equivalent? So if the
server is backed by a filesystem where write(2) preallocates space
surely the NFS server must behave as if it'spreallocating as well? I
would expect NFS to provide basically the same set of possible
failures as the underlying filesystem (as long as you don't enable
nosync of course).

-- 
greg