Blockchain synchronization fails, bus error

Question

I am using monerod 0.10.3.1 on Arch Linux. Towards the end of the process the synchronization with the blockchain fails:

2017-05-29 09:20:27.451 [P2P1]  WARN    net.dns 
src/common/dns_utils.cpp:531    WARNING: no two valid MoneroPulse DNS 
checkpoint records were received
2017-05-29 09:20:27.902 [P2P3]  INFO    global  
src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 
[66.228.41.201:18080 OUT] Sync data returned a new top block 
candidate: 1237496 -> 1320640 [Your node is 83144 blocks (115 days) 
behind] 
SYNCHRONIZATION started
 Bus error (core dumped)

Any idea what might be going wrong?

Answer 1

A bus error here is almost invariably due to a corrupt blockchain, so I'm afraid the only way out is to resync:

• delete the chain (the files in in ~/.bitmonero/lmdb)
• start monerod again, and wait for it to resync

You can get more info on that particular error, by running monerod again after running, in the same terminal: ulimit -c unlimited, then running gdb on the core which will be generated after the crash:

gdb monerod core*

Then, in gdb:

bt

You'll most likely find a stack trace crashing somewhere in the LMDB code, but if not, I'm interested to know where.

Answer 2

monero-gui-v0.18.3.1/monerod  --log-level 4
2024-03-07 22:22:22.529I Monero 'Fluorine Fermi' (v0.18.3.1-release)
2024-03-07 22:22:22.530I Moving from main() into the daemonize now.
2024-03-07 22:22:22.530I Initializing cryptonote protocol...
2024-03-07 22:22:22.530I Cryptonote protocol initialized OK
2024-03-07 22:22:22.530T Blockchain::Blockchain
2024-03-07 22:22:22.530I Initializing core...
2024-03-07 22:22:22.530T BlockchainLMDB::BlockchainLMDB
2024-03-07 22:22:22.530T BlockchainLMDB::get_db_name
2024-03-07 22:22:22.530I Loading blockchain from folder /home/wozza/.bitmonero/lmdb ...
2024-03-07 22:22:22.530D option: fast
2024-03-07 22:22:22.530D option: async
2024-03-07 22:22:22.530D option: 250000000bytes
2024-03-07 22:22:22.530T BlockchainLMDB::open
2024-03-07 22:22:22.530W The blockchain is on a rotating drive: this will be very slow, use an SSD if possible
2024-03-07 22:22:22.530T BlockchainLMDB::need_resize
2024-03-07 22:22:22.530D DB map size:     5090132736
2024-03-07 22:22:22.530D Space used:      3955585024
2024-03-07 22:22:22.530D Space remaining: 1134547712
2024-03-07 22:22:22.530D Size threshold:  0
2024-03-07 22:22:22.530D Percent used: 77.7108  Percent threshold: 90.0000
Bus error (core dumped)

• ✗ gdb monero-gui-v0.18.3.1/monerod core*

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    <http://www.gnu.org/software/gdb/documentation/>.

For help, type "help". Type "apropos word" to search for commands related to "word"... Reading symbols from monero-gui-v0.18.3.1/monerod... [New LWP 326598] [Thread debugging using libthread_db enabled] Using host libthread_db library "/usr/lib/x86_64-linux-gnu/libthread_db.so.1". Core was generated by `monero-gui-v0.18.3.1/monerod'. Program terminated with signal SIGBUS, Bus error.
#0  0x000055a5cf334f8a in mdb_page_search_root () (gdb) bt
#0  0x000055a5cf334f8a in mdb_page_search_root ()
#1  0x000055a5cf335165 in mdb_page_search ()
#2  0x000055a5cf3354bf in mdb_cursor_first ()
#3  0x000055a5cf33416b in mdb_cursor_get ()
#4  0x000055a5cf3345ee in mdb_page_alloc.isra ()
#5  0x000055a5cf33ae13 in mdb_cursor_touch ()
#6  0x000055a5cf33b430 in mdb_cursor_put ()
#7  0x000055a5cf33ef8a in mdb_dbi_open ()
#8  0x000055a5cf2ef96c in (anonymous namespace)::lmdb_db_open(MDB_txn*, char const*, int, unsigned int&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) ()
#9  0x000055a5cf32d134 in cryptonote::BlockchainLMDB::open(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, int) ()
#10 0x000055a5cf0a78d4 in cryptonote::core::init(boost::program_options::variables_map const&, cryptonote::test_options const*, std::function<epee::span<unsigned char const> const (cryptonote::network_type)> const&, bool) ()
#11 0x000055a5ced78950 in daemonize::t_core::t_core(boost::program_options::variables_map const&) ()
#12 0x000055a5ceda09d3 in daemonize::t_internals::t_internals(boost::program_options::variables_map const&) ()
#13 0x000055a5ced2406e in daemonize::t_daemon::t_daemon(boost::program_options::variables_map const&, unsigned short) ()
#14 0x000055a5ceda2054 in daemonize::t_executor::run_interactive(boost::program_options::variables_map const&) ()
#15 0x000055a5ceda56be in bool daemonizer::daemonize<daemonize::t_executor>(int, char const**, daemonize::t_executor&&, boost::program_options::variables_map const&) ()
#16 0x000055a5cecee98a in main ()