我们的环境中有一个简单的主/从集群，它设置在 Ubuntu 20.04 和 MariaDB 10.5 上：
MariaDB [(none)]> SELECT VERSION();
+--------------------------------------------+
| VERSION() |
+--------------------------------------------+
| 10.5.11-MariaDB-1:10.5.11+maria~bionic-log |
+--------------------------------------------+
我们将所有日志目录设置为/var/lib/mysql包括 bin log & relay log: /var/lib/mysql/binfiles。
对于这个目录 ( /var/lib/mysql)，我创建了一个 100GB 空间的 LVM，但是 2 天后，我收到了一条警报，说这个目录已满，我必须向它添加一个额外的 100GB 空间。
奇怪的是这个目录中的文件只使用了 18GB 磁盘空间，我不知道其余的发生了什么：
输出df -h：
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg--data-lv--mysql--log 99G 91G 3.4G 97% /var/log/mysql
输出du -h --max-depth=1 /var/log/mysql（包括隐藏文件；没有）：
13G /var/log/mysql/binfiles
19G /var/log/mysql
包含/var/log/mysql（包括隐藏文件；没有）：
total 5426300
drwxr-s--- 3 mysql adm 4096 Sep 23 00:18 .
drwxrwxr-x 10 root syslog 4096 Sep 23 00:18 ..
drwxr-sr-x 2 mysql adm 4096 Sep 23 12:21 binfiles
-rw-r----- 1 mysql adm 0 Sep 23 00:00 mariadb-slow.log
-rw-rw---- 1 mysql adm 14629234 Sep 23 00:00 mariadb-slow.log.1.gz
-rw-rw---- 1 mysql adm 1074177544 Sep 22 21:29 mariadb-slow.log.old
-rw-rw---- 1 mysql adm 33699 Sep 22 05:12 mariadb.err
-rw-r----- 1 mysql adm 0 Sep 23 00:00 mysql.log
-rw-rw---- 1 mysql adm 4467658081 Sep 23 00:00 mysql.log.1.gz
包含/etc/mysql/my.cnf：
# The MariaDB configuration file
#
# The MariaDB/MySQL tools read configuration files in the following order:
# 0. "/etc/mysql/my.cnf" symlinks to this file, reason why all the rest is read.
# 1. "/etc/mysql/mariadb.cnf" (this file) to set global defaults,
# 2. "/etc/mysql/conf.d/*.cnf" to set global options.
# 3. "/etc/mysql/mariadb.conf.d/*.cnf" to set MariaDB-only options.
# 4. "~/.my.cnf" to set user-specific options.
#
# If the same option is defined multiple times, the last one will apply.
#
# One can use all long options that the program supports.
# Run program with --help to get a list of available options and with
# --print-defaults to see which it would actually understand and use.
#
# If you are new to MariaDB, check out https://mariadb.com/kb/en/basic-mariadb-articles/
#
# This group is read both by the client and the server
# use it for options that affect everything
#
[client-server]
# Port or socket location where to connect
# port = 3306
socket = /run/mysqld/mysqld.sock
[client]
port = 3306
socket = /var/run/mysqld/mysqld.sock
[isamchk]
key_buffer = 16M
[mariabackup]
open_files_limit = 65535
[mysql]
#no-auto-rehash # faster start of mysql but no tab completion
[mysqld_safe]
socket = /var/run/mysqld/mysqld.sock
nice = 0
[mysqldump]
quick
quote-names
max_allowed_packet = 16M
# Import all .cnf files from configuration directory
!includedir /etc/mysql/conf.d/
!includedir /etc/mysql/mariadb.conf.d/
PS：示例中有一些配置文件/etc/mysql/mariadb.conf.d/，我已经注释了其中的所有配置。我的主要配置位于 2 个文件中/etc/mysql/conf.d/：mysqld.cnf&master.cnf
包含mysqld.cnf：
[mysqld]
# General
plugin_load_add = query_response_time
user = mysql
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
port = 3306
basedir = /usr
datadir = /var/lib/mysql
tmpdir = /tmp
lc_messages_dir = /usr/share/mysql
lc_messages = en_US
skip-external-locking
skip_name_resolve = 0
myisam_recover_options = BACKUP
concurrent_insert = 2
sql_mode = NO_ENGINE_SUBSTITUTION,NO_UNSIGNED_SUBTRACTION
default_storage_engine = InnoDB
performance_schema = ON
query_response_time_stats = ON
userstat = ON
innodb_buffer_pool_dump_at_shutdown = OFF
innodb_rollback_on_timeout = ON
# Performance
max_connections = 5000
connect_timeout = 5
wait_timeout = 600
max_allowed_packet = 100M
thread_cache_size = 128
sort_buffer_size = 4M
bulk_insert_buffer_size = 16M
tmp_table_size = 128M
max_heap_table_size = 128M
key_buffer_size = 128M
open-files-limit = 65535
table_open_cache = 2048
myisam_sort_buffer_size = 512M
read_buffer_size = 2M
read_rnd_buffer_size = 1M
query_cache_limit = 0
query_cache_size = 0
long_query_time = 0
join_buffer_size = 3M
table_definition_cache = 1424
# Innodb
innodb_buffer_pool_size = 186G
###innodb_buffer_pool_instances = 64
innodb_monitor_enable = all
innodb_file_per_table = 1
innodb_open_files = 65535
innodb_io_capacity = 30000
innodb_io_capacity_max = 40000
innodb_flush_neighbors = 0
innodb_flush_method = O_DIRECT
innodb_log_buffer_size = 8M
innodb_log_file_size = 6G
###innodb_log_files_in_group = 2
innodb_log_group_home_dir = /var/lib/mysql/
innodb_autoinc_lock_mode = 2
# Log
general_log = 1
general_log_file = /var/log/mysql/mysql.log
slow_query_log = 1
slow_query_log_file = /var/log/mysql/mariadb-slow.log
expire_logs_days = 5
log_error = /var/log/mysql/mariadb.err
log_warnings = 0
long_query_time = 0.5
#log_slow_rate_limit = 1000
log_queries_not_using_indexes = ON
log_slow_verbosity = query_plan,explain
log_slow_admin_statements = ON
log_slow_slave_statements = ON
log_bin = /var/log/mysql/binfiles/mariadb-bin
log_bin_index = /var/log/mysql/binfiles/mariadb-bin.index
max_binlog_size = 100M
binlog_format = row
relay_log = /var/log/mysql/binfiles/mariadb-relay-bin
relay_log_index = /var/log/mysql/binfiles/mariadb-relay-bin.index
max_relay_log_size = 100M
包含master.cnf：
[mysqld]
# Master/Slave settings for master node
bind-address = a.b.c.d
server-id = 10
gtid_domain_id = 0
log_slave_updates = 1
innodb_flush_log_at_trx_commit = 1
我认为这无关紧要，但我也在我的/etc/sysctl.conf文件中设置了这些：
net.core.somaxconn=65535
fs.file-max=2097152
fs.nr_open=2097152
vm.max_map_count=262144
net.core.rmem_max=16777216
net.core.wmem_max=16777216
net.core.rmem_default=262144
net.core.wmem_default=262144
net.ipv4.tcp_max_syn_backlog=65535
net.ipv4.tcp_fin_timeout=30
net.ipv4.tcp_syn_retries=2
net.core.netdev_max_backlog=300000
net.ipv4.ip_local_port_range=1024 65535
net.ipv4.tcp_wmem=8192 65536 16777216
net.ipv4.tcp_rmem=8192 87380 16777216
net.ipv4.tcp_keepalive_intvl=30
net.ipv4.tcp_keepalive_time=120
您能否指导我在/var/log/mysql没有其他文件时使用的空间以及如何修复它？
编辑 1：数据目录 ( /var/lib/mysql) 和日志目录 ( /var/log/mysql) 各有一个单独的分区；所以它必须是关于这个目录（/var/log/mysql）的东西，而不是其他东西。
更新 1：似乎当日志、慢日志和错误日志文件轮换时，mariadb 仍在使用它们，并且发生了这种情况。知道如何解决这个问题（显然我可以重新启动服务）？