linux 系统 磁盘标识含义 磁盘相关命令

sda:   linux系统的磁盘接口一上挂载的磁盘

sdb：linux系统的磁盘接口二上挂载的磁盘

dm:使用LVM对Linux下的物理盘进行逻辑分区，生成的表分区号，如dm-0,dm-1。。。

使用df命令检查文件系统的磁盘空间占用情况：df -h

使用fdisk -l查看分区表信息

计算方法：每秒采集一次/proc/diskstats，计算差值，都是计数器类型的。每个metric都会有一组tag描述，形如device=$device，用来表示具体的设备，比如sda1、sdb。用户可以参考iostat的帮助文档来理解具体的metric含义。

• disk.io.ios_in_progress：Number of actual I/O requests currently in flight.
• disk.io.msec_read：Total number of ms spent by all reads.
• disk.io.msec_total：Amount of time during which ios_in_progress >= 1.
• disk.io.msec_weighted_total：Measure of recent I/O completion time and backlog.
• disk.io.msec_write：Total number of ms spent by all writes.
• disk.io.read_merged：Adjacent read requests merged in a single req.
• disk.io.read_requests：Total number of reads completed successfully.
• disk.io.read_sectors：Total number of sectors read successfully.
• disk.io.write_merged：Adjacent write requests merged in a single req.
• disk.io.write_requests：total number of writes completed successfully.
• disk.io.write_sectors：total number of sectors written successfully.
• disk.io.read_bytes：单位是byte的数字
• disk.io.write_bytes：单位是byte的数字
• disk.io.avgrq_sz：下面几个值就是iostat -x 1看到的值
• disk.io.avgqu-sz
• disk.io.await
• disk.io.svctm
• disk.io.util：是个百分数，比如56.43，表示56.43%