On 7 Nov 1998, SL Baur wrote: > Justin Vallon <vallon(a)mindspring.com&gt; writes in xemacs-beta(a)xemacs.org: > > > I seem to remember somewhere that NFS writes may be postponed until > > close(). > > This brings back bad memories of old flame wars. I don't think NFS > will do this, but I know AFS can raise errors on close. If Dejanews > has restored enough old netnews, there should be megabytes on this > topic in the old archives. >

HP/UX 10.20, man close: ERRORS close() fails if the any of following conditions are encountered: ... [ENOSPC] Not enough space on the file system. This error can occur when closing a file on an NFS file system. [When a write() system call is executed on a local file system and if a new buffer needs to be allocated to hold the data, the buffer is mapped onto the disk at that time. A full disk is detected at this time and write() returns an error. When the write() system call is executed on an NFS file system, the new buffer is allocated without communicating with the NFS server to see if there is space for the buffer (to improve NFS performance). It is only when the buffer is written to the server (at file close or the buffer is full) that the disk-full condition is detected.] So, it appears that at least the HP NFS write() call can be cached and the cache is not write-through. Hence, a flush would most likely be required, or else stat() may be using a stale last-modify time.