illumos gate

I've reproduced this several times over the past two years.

I have an autofs-mounted NFSv4 share:
/net/nexentastor/export/ws on nexentastor:/export/ws remote/read/write/nosetuid/nodevices/xattr/dev=90c000c on Thu Sep 29 13:58:54 2011
A few days ago, I lost network connectivity for a few minutes (wireless network issues). The mountpoint is still held open by a process apparently. Stat'ing the directory hangs (but is interruptable).

Now snoop shows absolutely no network traffic, despite:
Oct 7 23:28:37 kirin nfs: [ID 733954 kern.info] NOTICE: [NFS4][Server: nexentastor][Mntpt: /net/nexentastor/export/ws]NFS server nexentastor not responding; still trying
Oct 8 11:31:54 kirin nfs: [ID 733954 kern.info] NOTICE: [NFS4][Server: nexentastor][Mntpt: /net/nexentastor/export/ws]NFS server nexentastor not responding; still trying

Trying to mount another share on the same server produces RPC errors:
[trisk@kirin]% pfexec mount nexentastor:/export/media /mnt ~/Downloads
NFS compound failed for server nexentastor: error 26 (RPC: Couldn't make connection)
NFS compound failed for server nexentastor: error 26 (RPC: Couldn't make connection)
NFS compound failed for server nexentastor: error 26 (RPC: Couldn't make connection)
NFS compound failed for server nexentastor: error 26 (RPC: Couldn't make connection)
NFS compound failed for server nexentastor: error 26 (RPC: Couldn't make connection)
NFS compound failed for server nexentastor: error 26 (RPC: Couldn't make connection)
nfs mount: mount: /mnt: I/O error
In syslog:
Oct 8 11:49:53 kirin nfs: [ID 664466 kern.notice] NFS compound failed for server nexentastor: error 26 (RPC: Couldn't make connection)
Oct 8 11:49:53 kirin genunix: [ID 664466 kern.notice] NFS compound failed for server nexentastor: error 26 (RPC: Couldn't make connection)
Oct 8 11:49:53 kirin nfs: [ID 434519 kern.warning] WARNING: NFS server initial call to nexentastor failed: I/O error

Mounting a share on a different NFSv4 server succeeds.