free命令可以查看当前系统的内存使用情况。
时间: 2024-01-21 21:19:56 浏览: 21
是的,`free` 命令可以查看当前系统的内存使用情况,包括总内存、已用内存、空闲内存、共享内存、缓冲区内存和缓存内存。可以使用以下命令来查看:
```
free -m
```
该命令会以兆字节(MB)为单位显示内存使用情况。
相关问题
利用free命令显示内存的使用情况。
可以在终端中输入以下命令来显示内存的使用情况:
```
free -h
```
其中,参数 `-h` 表示以可读性更好的方式显示输出结果。你可以在输出的结果中找到以下几个值:
- `total` 表示系统总共的内存大小
- `used` 表示当前正在使用的内存大小
- `free` 表示当前空闲的内存大小
- `shared` 表示多个进程共享使用的内存大小
- `buffers` 表示系统缓存的内存大小
- `cached` 表示系统缓存的页缓存大小
这些值的单位为GB,MB或KB,具体取决于内存的大小。
查看mysql 当前内存使用情况
可以使用以下命令查看 MySQL 当前内存使用情况:
```
SHOW STATUS LIKE 'Max_used_connections';
SHOW STATUS LIKE 'Threads_connected';
SHOW STATUS LIKE 'Threads_running';
SHOW STATUS LIKE 'Innodb_buffer_pool_pages_free';
SHOW STATUS LIKE 'Innodb_buffer_pool_pages_total';
SHOW STATUS LIKE 'Innodb_buffer_pool_read_requests';
SHOW STATUS LIKE 'Innodb_buffer_pool_reads';
SHOW STATUS LIKE 'Innodb_buffer_pool_write_requests';
SHOW STATUS LIKE 'Innodb_buffer_pool_writes';
SHOW STATUS LIKE 'Innodb_data_pending_fsyncs';
SHOW STATUS LIKE 'Innodb_data_pending_reads';
SHOW STATUS LIKE 'Innodb_data_pending_writes';
SHOW STATUS LIKE 'Innodb_data_read';
SHOW STATUS LIKE 'Innodb_data_reads';
SHOW STATUS LIKE 'Innodb_data_writes';
SHOW STATUS LIKE 'Innodb_data_written';
SHOW STATUS LIKE 'Innodb_log_waits';
SHOW STATUS LIKE 'Innodb_log_write_requests';
SHOW STATUS LIKE 'Innodb_log_writes';
SHOW STATUS LIKE 'Innodb_os_log_fsyncs';
SHOW STATUS LIKE 'Innodb_os_log_pending_fsyncs';
SHOW STATUS LIKE 'Innodb_os_log_written';
SHOW STATUS LIKE 'Innodb_page_size';
SHOW STATUS LIKE 'Innodb_pages_created';
SHOW STATUS LIKE 'Innodb_pages_read';
SHOW STATUS LIKE 'Innodb_pages_written';
SHOW STATUS LIKE 'Innodb_rows_deleted';
SHOW STATUS LIKE 'Innodb_rows_inserted';
SHOW STATUS LIKE 'Innodb_rows_read';
SHOW STATUS LIKE 'Innodb_rows_updated';
SHOW STATUS LIKE 'Key_blocks_not_flushed';
SHOW STATUS LIKE 'Key_blocks_unused';
SHOW STATUS LIKE 'Key_blocks_used';
SHOW STATUS LIKE 'Key_read_requests';
SHOW STATUS LIKE 'Key_reads';
SHOW STATUS LIKE 'Key_write_requests';
SHOW STATUS LIKE 'Key_writes';
SHOW STATUS LIKE 'Max_used_connections';
SHOW STATUS LIKE 'Open_files';
SHOW STATUS LIKE 'Open_streams';
SHOW STATUS LIKE 'Open_tables';
SHOW STATUS LIKE 'Opened_files';
SHOW STATUS LIKE 'Opened_table_definitions';
SHOW STATUS LIKE 'Opened_tables';
SHOW STATUS LIKE 'Qcache_free_memory';
SHOW STATUS LIKE 'Qcache_hits';
SHOW STATUS LIKE 'Qcache_inserts';
SHOW STATUS LIKE 'Qcache_lowmem_prunes';
SHOW STATUS LIKE 'Qcache_not_cached';
SHOW STATUS LIKE 'Qcache_queries_in_cache';
SHOW STATUS LIKE 'Qcache_total_blocks';
SHOW STATUS LIKE 'Queries';
SHOW STATUS LIKE 'Questions';
SHOW STATUS LIKE 'Select_full_join';
SHOW STATUS LIKE 'Select_full_range_join';
SHOW STATUS LIKE 'Select_range';
SHOW STATUS LIKE 'Select_range_check';
SHOW STATUS LIKE 'Select_scan';
SHOW STATUS LIKE 'Slave_running';
SHOW STATUS LIKE 'Slow_queries';
SHOW STATUS LIKE 'Sort_merge_passes';
SHOW STATUS LIKE 'Sort_range';
SHOW STATUS LIKE 'Sort_rows';
SHOW STATUS LIKE 'Sort_scan';
SHOW STATUS LIKE 'Table_locks_immediate';
SHOW STATUS LIKE 'Table_locks_waited';
SHOW STATUS LIKE 'Threads_cached';
SHOW STATUS LIKE 'Threads_created';
SHOW STATUS LIKE 'Threads_connected';
SHOW STATUS LIKE 'Threads_running';
```
其中,比较重要的指标包括:
- Innodb_buffer_pool_pages_free:InnoDB 缓冲池中空闲的页数。
- Innodb_buffer_pool_pages_total:InnoDB 缓冲池中总的页数。
- Innodb_buffer_pool_read_requests:InnoDB 读取缓冲池中的逻辑请求次数。
- Innodb_buffer_pool_reads:InnoDB 从磁盘读取的物理页数。
- Innodb_buffer_pool_write_requests:InnoDB 写入缓冲池中的逻辑请求次数。
- Innodb_buffer_pool_writes:InnoDB 从缓冲池中写入磁盘的物理页数。
通过观察这些指标可以大致了解 MySQL 的内存使用情况。