Cannot lock data directory over NFS [0.17.1][0.17.0.1] #15058

ISSUE

Data directory locking fails over NFS

CONTEXT

# data directory
ls -ahl
total 12M
drwxrwx--- 5 bitcoin bitcoin   10 Dec 29 09:50 .
drwxrwx--- 3 bitcoin bitcoin    3 Dec 29 07:22 ..
-rw-rw---- 1 bitcoin bitcoin  12K Dec 29 07:22 banlist.dat
drwxrwx--- 3 bitcoin bitcoin 2.9K Dec 29 08:03 blocks
drwxrwx--- 2 bitcoin bitcoin 1.4K Dec 29 08:08 chainstate
-rw-rw---- 1 bitcoin bitcoin 9.6M Dec 29 07:22 debug.log
-rw-rw---- 1 bitcoin bitcoin 243K Dec 29 07:22 fee_estimates.dat
-rw-rw---- 1 bitcoin bitcoin 6.4M Dec 29 07:22 mempool.dat
-rw-rw---- 1 bitcoin bitcoin 4.7M Dec 29 07:22 peers.dat
drwxrwx--- 4 bitcoin bitcoin   13 Dec 29 08:12 testnet3

Dec 29 17:50:50 bitcoin systemd[1]: Started BitcoinD Mainnet.
Dec 29 17:50:50 bitcoin bitcoind[567]: 2018-12-29T17:50:50Z Bitcoin Core version v0.17.0.1 (release build)
Dec 29 17:50:50 bitcoin bitcoind[567]: 2018-12-29T17:50:50Z InitParameterInteraction: parameter interaction: -whitelistforcerelay=1 -> setting -whitelistrelay=1
Dec 29 17:50:50 bitcoin bitcoind[567]: 2018-12-29T17:50:50Z Assuming ancestors of block 0000000000000000002e63058c023a9a1de233554f28c7b21380b6c9003f36a8 have valid signatures.
Dec 29 17:50:50 bitcoin bitcoind[567]: 2018-12-29T17:50:50Z Setting nMinimumChainWork=0000000000000000000000000000000000000000028822fef1c230963535a90d
Dec 29 17:50:50 bitcoin bitcoind[567]: 2018-12-29T17:50:50Z Using the 'sse4(1way),sse41(4way),avx2(8way)' SHA256 implementation
Dec 29 17:50:50 bitcoin bitcoind[567]: 2018-12-29T17:50:50Z Using RdRand as an additional entropy source
Dec 29 17:50:56 bitcoin bitcoind[567]: 2018-12-29T17:50:56Z ERROR: Error while attempting to lock directory /mnt/bitcoin/bitcoind/data/: No locks available
Dec 29 17:50:56 bitcoin bitcoind[567]: 2018-12-29T17:50:56Z Error: Cannot obtain a lock on data directory /mnt/bitcoin/bitcoind/data/. Bitcoin Core is probably already running.
Dec 29 17:50:56 bitcoin bitcoind[567]: Error: Cannot obtain a lock on data directory /mnt/bitcoin/bitcoind/data/. Bitcoin Core is probably already running.

# data directory lock
ls -ahl
total 12M
drwxrwx--- 5 bitcoin bitcoin   11 Dec 29 09:53 .
drwxrwx--- 3 bitcoin bitcoin    3 Dec 29 07:22 ..
-rw-rw---- 1 bitcoin bitcoin  12K Dec 29 07:22 banlist.dat
drwxrwx--- 3 bitcoin bitcoin 2.9K Dec 29 08:03 blocks
drwxrwx--- 2 bitcoin bitcoin 1.4K Dec 29 08:08 chainstate
-rw-rw---- 1 bitcoin bitcoin 9.6M Dec 29 07:22 debug.log
-rw-rw---- 1 bitcoin bitcoin 243K Dec 29 07:22 fee_estimates.dat
-rw------- 1 bitcoin bitcoin    0 Dec 29 09:50 .lock
-rw-rw---- 1 bitcoin bitcoin 6.4M Dec 29 07:22 mempool.dat
-rw-rw---- 1 bitcoin bitcoin 4.7M Dec 29 07:22 peers.dat
drwxrwx--- 4 bitcoin bitcoin   13 Dec 29 08:12 testnet3

Pretty sure this is a NFS issue, not bitcoind.

https://serverfault.com/questions/61594/what-does-no-locks-available-mean

Dec 29 16:43:35 <server1> kernel: [ 3114.560194] lockd: cannot monitor <server2>

huh, yeah, it is an nfs issue. turns out someone in systemd disabled statd service by default.

Sorry for the bother.