On Tue, Jun 18, 2019 at 11:29:16AM -0400, Benjamin Coddington wrote: > I think that your transport or NFS server is dropping the response to an > RPC. The NFS client will not retransmit on an established connection. > > What server are you using? Any middle boxes on the network that could be > transparently dropping transmissions (less likely, but I have seen them)? > I've found 8 separate NFS client hangs of the sort I reported here, and in all cases the same NFS server was involved: an Ubuntu Trusty system running 4.4.0. I've been upgrading all of these NFS servers, haven't done this one yet--the complicity of NFS hangs I've been seeing have slowed me down. Of the 8 NFS clients with a hang to this server, about half are in the same computer room where packets only transit rack switches, with the other half also going through a computer room router. I see positive dropped and overrun packet counts on the NFS server interface, along with a similar magnitude of pause counts on the switch port for the NFS server. Given the occurences of this issue only this rack switch and a redundant pair of top-of-rack switches in the rack with the NFS server are in-common between all 8 NFS clients with write hangs. -A -- Alan Post | Xen VPS hosting for the technically adept PO Box 61688 | Sunnyvale, CA 94088-1681 | https://prgmr.com/ email: adp@xxxxxxxxx
