Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.debian.bugs.dist > #1154664

Bug#1040343: linux-image-5.10.0-9-amd64: Kernel silenty de-supported nfsv3 UDP mounts

Cross-posted to 2 groups.

Show all headers | View raw

[Multipart message — attachments visible in raw view] - view raw

On Mon, 2023-07-17 at 09:05 +0200, Hauke Fath wrote:
> On Sun, 16 Jul 2023 20:14:20 +0200, Ben Hutchings wrote:
> > > 
> > > nfsv3 over tcp works, but is subobtimal , as described - when the router 
> > > goes down, the tcp mounts will hang, and the machine will have to be 
> > > rebooted.
> > [...]
> > 
> > Does this mean you are using the "soft" mount option?  Without that, I
> > would expect access to the mount to hang until the network connection
> > is restored, regardless of whether the TCP or UDP transport is used.
> 
> No, we use hard mounts.
> 
> But the router's package filter will have lost state after a reboot, 
> and reject packets from tcp connections that the clients assume to 
> exist. This is not a problem with udp, because connection-less.

Ah, I see.  You didn't mention that there was dynamic NAT involved
before.

If an NFS server is rebooted abruptly (so it doesn't properly close TCP
connections), once it's back up it will respond to any requests from
clients with a TCP RST, and they should reconnect.

If a NAT router between client and server is rebooted, I think that
something similar should happen, but the router would need to send the
TCP RST instead.

Is your router configured to send a TCP RST when receiving a packet for
an unknown connection, or does it just drop those packets?  (In
iptables this is the difference between REJECT and DROP policies.)

Ben.

-- 
Ben Hutchings
Never attribute to conspiracy what can adequately be explained
by stupidity.

Back to linux.debian.bugs.dist | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Bug#1040343: linux-image-5.10.0-9-amd64: Kernel silenty de-supported nfsv3 UDP mounts Hauke Fath <hf@spg.tu-darmstadt.de> - 2023-07-04 18:50 +0200
  Bug#1040343: linux-image-5.10.0-9-amd64: Kernel silenty de-supported nfsv3 UDP mounts Bastian Blank <waldi@debian.org> - 2023-07-05 10:30 +0200
    Bug#1040343: linux-image-5.10.0-9-amd64: Kernel silenty de-supported nfsv3 UDP mounts Hauke Fath <hf@spg.tu-darmstadt.de> - 2023-07-05 15:40 +0200
      Bug#1040343: linux-image-5.10.0-9-amd64: Kernel silenty de-supported nfsv3 UDP mounts Ben Hutchings <ben@decadent.org.uk> - 2023-07-16 20:20 +0200
        Bug#1040343: linux-image-5.10.0-9-amd64: Kernel silenty de-supported nfsv3 UDP mounts Hauke Fath <hf@spg.tu-darmstadt.de> - 2023-07-17 09:20 +0200
          Bug#1040343: linux-image-5.10.0-9-amd64: Kernel silenty de-supported nfsv3 UDP mounts Ben Hutchings <ben@decadent.org.uk> - 2023-07-17 20:40 +0200
            Bug#1040343: linux-image-5.10.0-9-amd64: Kernel silenty de-supported nfsv3 UDP mounts Hauke Fath <hf@spg.tu-darmstadt.de> - 2023-07-18 12:40 +0200

csiph-web