Mysqld crashes on start

Question

Since my last system upgrade mysqld refuses to start.
Mar 23 14:48:28 Fenix mysqld[424]: 130323 14:48:28 InnoDB: Waiting for the background threads to start
Mar 23 14:48:29 Fenix mysqld[424]: 130323 14:48:29 InnoDB: 5.5.30 started; log sequence number 54315694
Mar 23 14:48:29 Fenix mysqld[424]: 13:48:29 UTC - mysqld got signal 11 ;
Mar 23 14:48:29 Fenix mysqld[424]: This could be because you hit a bug. It is also possible that this binary
Mar 23 14:48:29 Fenix mysqld[424]: or one of the libraries it was linked against is corrupt, improperly built,
Mar 23 14:48:29 Fenix mysqld[424]: or misconfigured. This error can also be caused by malfunctioning hardware.
Mar 23 14:48:29 Fenix mysqld[424]: We will try our best to scrape up some info that will hopefully help
Mar 23 14:48:29 Fenix mysqld[424]: diagnose the problem, but since we have already crashed,
Mar 23 14:48:29 Fenix mysqld[424]: something is definitely wrong and this may fail.
Mar 23 14:48:29 Fenix mysqld[424]: key_buffer_size=16777216
Mar 23 14:48:29 Fenix mysqld[424]: read_buffer_size=262144
Mar 23 14:48:29 Fenix mysqld[424]: max_used_connections=0
Mar 23 14:48:29 Fenix mysqld[424]: max_threads=151
Mar 23 14:48:29 Fenix mysqld[424]: thread_count=0
Mar 23 14:48:29 Fenix mysqld[424]: connection_count=0
Mar 23 14:48:29 Fenix mysqld[424]: It is possible that mysqld could use up to
Mar 23 14:48:29 Fenix mysqld[424]: key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 134074 K byte
Mar 23 14:48:29 Fenix mysqld[424]: Hope that's ok; if not, decrease some variables in the equation.
Mar 23 14:48:29 Fenix mysqld[424]: Thread pointer: 0x0
Mar 23 14:48:29 Fenix mysqld[424]: Attempting backtrace. You can use the following information to find out
Mar 23 14:48:29 Fenix mysqld[424]: where mysqld died. If you see no messages after this, something went
Mar 23 14:48:29 Fenix mysqld[424]: terribly wrong...
Mar 23 14:48:29 Fenix mysqld[424]: stack_bottom = 0 thread_stack 0x40000
Mar 23 14:48:29 Fenix mysqld[424]: /usr/bin/mysqld(my_print_stacktrace+0x29)[0x78ae99]
Mar 23 14:48:29 Fenix mysqld[424]: /usr/bin/mysqld(handle_fatal_signal+0x471)[0x67ad71]
Mar 23 14:48:29 Fenix mysqld[424]: /usr/lib/libpthread.so.0(+0xf1e0)[0x7fecdc88d1e0]
Mar 23 14:48:29 Fenix mysqld[424]: The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains
Mar 23 14:48:29 Fenix mysqld[424]: information that should help you find out what is causing the crash.
Mar 23 14:48:29 Fenix systemd[1]: mysqld.service: main process exited, code=exited, status=1/FAILURE
I have to see I can extract very little useful information from this log. Anyone?

Answer 1

ES wrote:Just in case it can helps someone, I had the same kind of errors and the cause was a full var partition.
A `pacman -Sc` fixed it for me.
Just wanted to say thanks for this - this fixed a similar problem I had with mysqld not starting after a recent pacman update:
[alexdw@AlexPC ~]$ sudo systemctl status mysqld.service -l
mysqld.service - MariaDB database server
Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled)
Active: activating (start-post) (Result: exit-code) since Mon 2014-01-06 10:52:29 GMT; 21s ago
Process: 1088 ExecStart=/usr/bin/mysqld --pid-file=/run/mysqld/mysqld.pid (code=exited, status=1/FAILURE)
Main PID: 1088 (code=exited, status=1/FAILURE); : 1089 (mysqld-post)
CGroup: /system.slice/mysqld.service
└─control
├─1089 /bin/sh /usr/bin/mysqld-post
└─1965 sleep 1
Jan 06 10:52:29 AlexPC mysqld[1088]: 140106 10:52:29 [ERROR] Plugin 'InnoDB' init function returned error.
Jan 06 10:52:29 AlexPC mysqld[1088]: 140106 10:52:29 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
Jan 06 10:52:29 AlexPC mysqld[1088]: 140106 10:52:29 [ERROR] mysqld: Got error 'Size of control file is smaller than expected' when trying to use aria control file '/var/lib/mysql/aria_log_control'
Jan 06 10:52:29 AlexPC mysqld[1088]: 140106 10:52:29 [ERROR] Plugin 'Aria' init function returned error.
Jan 06 10:52:29 AlexPC mysqld[1088]: 140106 10:52:29 [ERROR] Plugin 'Aria' registration as a STORAGE ENGINE failed.
Jan 06 10:52:29 AlexPC mysqld[1088]: 140106 10:52:29 [Note] Plugin 'FEEDBACK' is disabled.
Jan 06 10:52:29 AlexPC mysqld[1088]: 140106 10:52:29 [ERROR] Unknown/unsupported storage engine: InnoDB
Jan 06 10:52:29 AlexPC mysqld[1088]: 140106 10:52:29 [ERROR] Aborting
Jan 06 10:52:29 AlexPC mysqld[1088]: 140106 10:52:29 [Note] /usr/bin/mysqld: Shutdown complete
Jan 06 10:52:29 AlexPC systemd[1]: mysqld.service: main process exited, code=exited, status=1/FAILURE