I am using centos 6 and ı have this problem today?
# mysql --version
mysql Ver 14.14 Distrib 5.5.53, for Linux (x86_64) using readline 5.1
cat /var/log/mysqld.log
170921 21:44:32 [ERROR] /usr/libexec/mysqld: Error writing file '/var/run/mysqld/mysqld.pid' (Errcode: 28)
170921 21:44:32 [ERROR] Can't start server: can't create PID file: No space left on device
170921 21:44:33 mysqld_safe Number of processes running now: 0
170921 21:44:33 mysqld_safe mysqld restarted
170921 21:44:33 [Note] /usr/libexec/mysqld (mysqld 5.5.53) starting as process 11361 ...
170921 21:44:33 [Note] Plugin 'FEDERATED' is disabled.
170921 21:44:33 InnoDB: The InnoDB memory heap is disabled
170921 21:44:33 InnoDB: Mutexes and rw_locks use GCC atomic builtins
170921 21:44:33 InnoDB: Compressed tables use zlib 1.2.3
170921 21:44:33 InnoDB: Using Linux native AIO
170921 21:44:33 InnoDB: Initializing buffer pool, size = 128.0M
170921 21:44:33 InnoDB: Completed initialization of buffer pool
170921 21:44:33 InnoDB: highest supported file format is Barracuda.
InnoDB: The log sequence number in ibdata files does not match
InnoDB: the log sequence number in the ib_logfiles!
170921 21:44:33 InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the 170921 21:44:34 mysqld_safe Number of processes running now: 0
170921 21:44:34 mysqld_safe mysqld restarted
170921 21:44:34 [Note] /usr/libexec/mysqld (mysqld 5.5.53) starting as process 11394 ...
170921 21:44:34 [Note] Plugin 'FEDERATED' is disabled.
170921 21:44:34 InnoDB: The InnoDB memory heap is disabled
170921 21:44:34 InnoDB: Mutexes and rw_locks use GCC atomic builtins
170921 21:44:34 InnoDB: Compressed tables use zlib 1.2.3
170921 21:44:34 InnoDB: Using Linux native AIO
170921 21:44:34 InnoDB: Initializing buffer pool, size = 128.0M
170921 21:44:34 InnoDB: Completed initialization of buffer pool
170921 21:44:34 InnoDB: highest supported file format is Barracuda.
InnoDB: The log sequence number in ibdata files does not match
InnoDB: the log sequence number in the ib_logfiles!
170921 21:44:34 InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Restoring possible half-written data pages from the doublewrite
InnoDB: buffer...
170921 21:44:34 InnoDB: Waiting for the background threads to start
170921 21:44:35 InnoDB: 5.5.53 started; log sequence number 551980342
170921 21:44:35 [Note] Server hostname (bind-address): '0.0.0.0'; port: 3306
170921 21:44:35 [Note] - '0.0.0.0' resolves to '0.0.0.0';
170921 21:44:35 [Note] Server socket created on IP: '0.0.0.0'.
170921 21:44:35 [ERROR] /usr/libexec/mysqld: Error writing file '/var/run/mysqld/mysqld.pid' (Errcode: 28)
170921 21:44:35 [ERROR] Can't start server: can't create PID file: No space left on device
170921 21:44:35 mysqld_safe Number of processes running now: 0
170921 21:44:35 mysqld_safe mysqld restarted
170921 21:44:35 [Note] /usr/libexec/mysqld (mysqld 5.5.53) starting as process 11426 ...
170921 21:44:35 [Note] Plugin 'FEDERATED' is disabled.
170921 21:44:35 InnoDB: The InnoDB memory heap is disabled
170921 21:44:35 InnoDB: Mutexes and rw_locks use GCC atomic builtins
170921 21:44:35 InnoDB: Compressed tables use zlib 1.2.3
170921 21:44:35 InnoDB: Using Linux native AIO
170921 21:44:35 InnoDB: Initializing buffer pool, size = 128.0M
170921 21:44:35 InnoDB: Completed initialization of buffer pool
170921 21:44:35 InnoDB: highest supported file format is Barracuda.
InnoDB: The log sequence number in ibdata files does not match
InnoDB: the log sequence number in the ib_logfiles!
170921 21:44:35 InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Restoring possible half-written data pages from the doublewrite
InnoDB: buffer...
170921 21:44:35 InnoDB: Waiting for the background threads to start