Sorry about that. I was having tunnel vision and pulled out the part that applied to me. I also figured that the OS and file system information was superfluous but on second look it may not be. This bit:
To satisfy the Durability requirement, all write operations must write through any OS cache to stable storage before they are reported as complete or otherwise made visible. Write-back caching behavior is prohibited, and data from failed writes must not appear in an OS cache. To satisfy the Serialization requirements, any OS cache must be fully coherent with the underlying storage. For instance, each write must invalidate any OS-cached copies of the data to be overwritten, on any and all hosts, prior to commitment. Multiple hosts may access the same storage concurrently under shared-disk clustering, such as that implemented by Oracle RAC and/or ASM.
Sounds kind of scary. I think postgres forces the underlying OS and file system to do that stuff (sans the mutli-host magic) using fsync. Is that right?
It does look like there are some gotchas with NFS.