Total DISK READ :       0.00 B/s | Total DISK WRITE :    1794.15 K/s
Actual DISK READ:       0.00 B/s | Actual DISK WRITE:       2.27 M/s
  TID  PRIO  USER     DISK READ  DISK WRITE  SWAPIN     IO>    COMMAND                                                                                    
  406 be/3 root        0.00 B/s    3.57 K/s  0.00 % 40.46 % [jbd2/sda3-8]
11926 be/4 mysql       0.00 B/s  399.49 K/s  0.00 %  5.28 % mysqld --basedir=/usr --datadir=/var/lib/mysql~t=100000 --pid-file=/var/run/mariadb/mysqld.pid
11911 be/4 mysql       0.00 B/s  413.76 K/s  0.00 %  3.91 % mysqld --basedir=/usr --datadir=/var/lib/mysql~t=100000 --pid-file=/var/run/mariadb/mysqld.pid
11916 be/4 mysql       0.00 B/s  114.14 K/s  0.00 %  2.05 % mysqld --basedir=/usr --datadir=/var/lib/mysql~t=100000 --pid-file=/var/run/mariadb/mysqld.pid
11906 be/4 mysql       0.00 B/s   85.61 K/s  0.00 %  1.80 % mysqld --basedir=/usr --datadir=/var/lib/mysql~t=100000 --pid-file=/var/run/mariadb/mysqld.pid
11786 be/4 mysql       0.00 B/s  128.41 K/s  0.00 %  1.65 % mysqld --basedir=/usr --datadir=/var/lib/mysql~t=100000 --pid-file=/var/run/mariadb/mysqld.pid
11920 be/4 mysql       0.00 B/s  199.75 K/s  0.00 %  1.65 % mysqld --basedir=/usr --datadir=/var/lib/mysql~t=100000 --pid-file=/var/run/mariadb/mysqld.pid
11692 be/4 mysql       0.00 B/s   57.07 K/s  0.00 %  1.27 % mysqld --basedir=/usr --datadir=/var/lib/mysql~t=100000 --pid-file=/var/run/mariadb/mysqld.pid
11756 be/4 mysql       0.00 B/s  171.21 K/s  0.00 %  1.24 % mysqld --basedir=/usr --datadir=/var/lib/mysql~t=100000 --pid-file=/var/run/mariadb/mysqld.pid
11173 be/4 mysql       0.00 B/s   57.07 K/s  0.00 %  0.85 % mysqld --basedir=/usr --datadir=/var/lib/mysql~t=100000 --pid-file=/var/run/mariadb/mysqld.pid
11923 be/4 mysql       0.00 B/s   57.07 K/s  0.00 %  0.74 % mysqld --basedir=/usr --datadir=/var/lib/mysql~t=100000 --pid-file=/var/run/mariadb/mysqld.pid
11908 be/4 mysql       0.00 B/s   28.54 K/s  0.00 %  0.73 % mysqld --basedir=/usr --datadir=/var/lib/mysql~t=100000 --pid-file=/var/run/mariadb/mysqld.pid
11927 be/4 mysql       0.00 B/s   28.54 K/s  0.00 %  0.53 % mysqld --basedir=/usr --datadir=/var/lib/mysql~t=100000 --pid-file=/var/run/mariadb/mysqld.pid
11934 be/4 mysql       0.00 B/s    3.57 K/s  0.00 %  0.19 % mysqld --basedir=/usr --datadir=/var/lib/mysql~t=10

Zabbix сервер, место на диске есть, более 500 гигабайт свободно

/dev/sda3 on / type ext4 (rw,noatime,nodiratime,data=ordered)

База большая 380 гигов, куда посмотреть.

cat /etc/my.cnf
[mysqld]
datadir=/var/lib/mysql
innodb_use_native_aio=1
skip-log-bin
#datadir=/mnt/mysql
# socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
default_storage_engine=InnoDB
innodb_file_per_table = 1
#
tmpdir=/mytmp
#
# network
connect_timeout = 60
wait_timeout = 28800
max_connections = 2048
max_allowed_packet = 64M
max_connect_errors = 1000

# limits
tmp_table_size = 512M
max_heap_table_size = 256M
table_cache = 512

# logs
# log_error = /var/log/mysql-error.log
slow_query_log_file = /var/log/mariadb/mysql-slow.log
slow_query_log = 1
long_query_time = 20
#log-bin=mysql-bin
#log-bin=/var/lib/mysql_innodblog/mysql-bin
log-bin = /var/backups/mysql/mysql_innodblog/mysql-bin
log-bin-index = /var/backups/mysql/mysql_innodblog/mysql-bin.index

join_buffer_size=2048k
read_buffer_size=256k
read_rnd_buffer_size=256k

# innodb
default_storage_engine=InnoDB
innodb_file_per_table = 1
innodb_status_file = 1
innodb_additional_mem_pool_size = 128M
innodb_buffer_pool_size = 24G
innodb_buffer_pool_instances = 24
innodb_flush_method = O_DIRECT
innodb_io_capacity = 2000
innodb_flush_log_at_trx_commit = 2
innodb_support_xa = 0
innodb_log_buffer_size = 1024M
## innodb_data_file_path  = ibdata1:128M;ibdata2:128M:autoextend:max:4096M

# experimental
innodb_stats_update_need_lock = 0

# other stuff
event_scheduler = 1
query_cache_type = 0
query_cache_size = 536870912
join_buffer_size=1M
query_cache_limit=2M
sort_buffer_size=2M
read_buffer_size=2M
read_rnd_buffer_size=4M
key_buffer = 256M
key_buffer_size=64M
open_files_limit = 100000
thread_cache_size = 4

[mysqld_safe]
# log-error=/var/log/mysqld.log
pid-file=/var/run/mariadb/mysqld.pid

#
# include all files from the config directory
#
!includedir /etc/my.cnf.d

Диски быстрые в 10 RAID, 600 gb 10000rpm, raid показывает что все норм с дисками и самим контроллером.