每当我尝试从phpmyadmin中的百万行中选择我的Mysql表时，我收到以下错误： “写入文件/ tmp / Errcode 28时出错”
服务器统计信息：
Filesystem Size Used Avail Use% Mounted on
/dev/vda1 30G 21G 7.5G 74% /
tmpfs 939M 0 939M 0% /dev/shm
/usr/tmpDSK 3.0G 176M 2.6G 7% /tmp
的my.cnf
[mysqld]
tmpdir=/tmp
innodb_file_per_table=1
open_files_limit=50000
myisam_use_mmap=1
max_connections = 200
max_user_connections = 75
join_buffer_size=2M
sort_buffer_size=2M
table_open_cache = 8000
table_definition_cache = 6000
max_allowed_packet = 1G
thread_cache_size = 384
query_cache_type = 1
query_cache_size = 100M
query_cache_limit = 1M
max_heap_table_size = 50M
tmp_table_size = 300M
key_buffer_size = 2500M
innodb_buffer_pool_size = 3G
innodb_log_buffer_size = 32M
innodb_old_blocks_time=1000
innodb_concurrency_tickets=5000
innodb_autoextend_increment=64M
innodb_open_files=2000
innodb_stats_on_metadata=0
slow_query_log=1
slow_query_log_file=mysql-slow.log
long_query_time=0.1
一般统计--------------------------------------------- -----
[--] Skipped version check for MySQLTuner script
[OK] Currently running supported MySQL version 5.5.35-cll
[OK] Operating on 64-bit architecture
-------- Storage Engine Statistics -------------------------------------------
[--] Status: +Archive -BDB -Federated +InnoDB -ISAM -NDBCluster
[--] Data in MyISAM tables: 6G (Tables: 293)
[--] Data in InnoDB tables: 224K (Tables: 14)
[--] Data in PERFORMANCE_SCHEMA tables: 0B (Tables: 17)
[!!] Total fragmented tables: 45
-------- Security Recommendations -------------------------------------------
[OK] All database users have passwords assigned
-------- Performance Metrics -------------------------------------------------
[--] Up for: 37m 24s (909 q [0.405 qps], 127 conn, TX: 608K, RX: 75K)
[--] Reads / Writes: 68% / 32%
[--] Total buffers: 5.6G global + 4.6M per thread (200 max threads)
[!!] Maximum possible memory usage: 6.5G (356% of installed RAM)
[OK] Slow queries: 4% (39/909)
[OK] Highest usage of available connections: 6% (13/200)
[OK] Key buffer size / total MyISAM indexes: 2.4G/2.4G
[!!] Key buffer hit rate: 85.3% (685 cached / 101 reads)
[OK] Query cache efficiency: 47.4% (225 cached / 475 selects)
[OK] Query cache prunes per day: 0
[OK] Sorts requiring temporary tables: 0% (0 temp sorts / 12 sorts)
[OK] Temporary tables created on disk: 11% (2 on disk / 17 total)
[OK] Thread cache hit rate: 89% (13 created / 127 connections)
[OK] Table cache hit rate: 98% (379 open / 386 opened)
[OK] Open file limit used: 1% (666/50K)
[!!] Table locks acquired immediately: 93%
[OK] InnoDB data size / buffer pool: 224.0K/3.0G
如何调整服务器以管理此类表格，以便：“写入文件/ tmp / Errcode 28时出错”不会出现？我有几个这样的表。
谢谢。