system service►CentOS►linux 磁盘系统block区别

linux 磁盘系统block区别

linux磁盘block和系统block区别

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磁盘里面和文件系统里面都有一个叫"block size"的值,但它们的大小不一定一样.
磁盘里面一般都是512bytes;文件系统里面的不一定也是512bytes,一般是1024bytes

例如:
[root@dev ~]# fdisk -l /dev/vda
Disk /dev/vda: 21.5 GB, 21474836480 bytes, 41943040 sectors
Units = sectors of 1 * 512 = 512 bytes   # 512 表示单个磁盘 block 是 512字节
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x0009d5a6

   Device Boot      Start         End      Blocks   Id  System
/dev/vda1   *        2048     1026047      512000   83  Linux
/dev/vda2         1026048    41943039    20458496   8e  Linux LVM


[root@dev ~]# tune2fs -l /dev/vda1 |grep "Block size"
Block size:               1024