I have seen it several times that one of my nodes got stuck with a bazillion of messages like

Mar 12 00:00:02 srvl062 kernel: [713683.338101] nfs: server 10.43.170.7 not responding, timed out
Mar 12 00:00:03 srvl062 kernel: [713683.914078] nfs: server 10.43.187.251 not responding, timed out
Mar 12 00:00:03 srvl062 kernel: [713684.170058] nfs: server 10.43.28.105 not responding, timed out
Mar 12 00:00:05 srvl062 kernel: [713685.453982] nfs: server 10.43.86.90 not responding, timed out
Mar 12 00:00:05 srvl062 kernel: [713685.610363] nfs: server 10.43.133.91 not responding, timed out
Mar 12 00:00:05 srvl062 kernel: [713686.217960] nfs: server 10.43.28.71 not responding, timed out
Mar 12 00:00:06 srvl062 kernel: [713687.245956] nfs: server 10.43.43.8 not responding, timed out
Mar 12 00:00:08 srvl062 kernel: [713689.289855] nfs: server 10.43.131.82 not responding, timed out
Mar 12 00:00:10 srvl062 kernel: [713690.501785] nfs: server 10.43.170.7 not responding, timed out
Mar 12 00:00:10 srvl062 kernel: [713690.569795] nfs: server 10.43.86.90 not responding, timed out
Mar 12 00:00:13 srvl062 kernel: [713693.385742] nfs: server 10.43.187.251 not responding, timed out
Mar 12 00:00:13 srvl062 kernel: [713694.185659] nfs: server 10.43.43.8 not responding, timed out
Mar 12 00:00:14 srvl062 kernel: [713695.013664] nfs: server 10.43.28.105 not responding, timed out
Mar 12 00:00:15 srvl062 kernel: [713695.693620] nfs: server 10.43.86.90 not responding, timed out
Mar 12 00:00:16 srvl062 kernel: [713696.521595] nfs: server 10.43.133.91 not responding, timed out
Mar 12 00:00:20 srvl062 kernel: [713700.557466] nfs: server 10.43.170.165 not responding, timed out
Mar 12 00:00:20 srvl062 kernel: [713700.617405] nfs: server 10.43.86.90 not responding, timed out
Mar 12 00:00:20 srvl062 kernel: [713700.813461] nfs: server 10.43.131.82 not responding, timed out
Mar 12 00:00:21 srvl062 kernel: [713701.641479] nfs: server 10.43.187.251 not responding, timed out
Mar 12 00:00:22 srvl062 kernel: [713703.241337] nfs: server 10.43.70.182 not responding, timed out
Mar 12 00:00:24 srvl062 kernel: [713704.717343] nfs: server 10.43.170.7 not responding, timed out
Mar 12 00:00:25 srvl062 kernel: [713705.485281] nfs: server 10.43.202.97 not responding, timed out

What is the recommended procedure to get out of this?