文件系统-1-相关节点和命令

一、文件节点

1. /proc/partitions

/ # cat /proc/partitions
major minor  #blocks  name

   1        0       8192 ram0 ...
   1       15       8192 ram15
 254        0   10485760 vda ...
 254      304      98304 vdt
 253        0    6291456 zram0
 252        0    5298756 dm-0 ...
 252        5     324420 dm-5

创建位置 block/genhd.c。通过此文件可以获取系统磁盘的分区信息。每一行表示一个磁盘分区，内容分别为主设备号、次设备号、分区大小等信息。

2. /proc/diskstats

/ # cat /proc/diskstats
   1       0 ram0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
   7     120 loop15 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 254       0 vda 32037 1846 3952896 23666 0 0 0 0 0 24444 1804 0 0 0 0
 254     304 vdt 1 0 8 0 0 0 0 0 0 4 0 0 0 0 0
 253       0 zram0 106238 0 849904 892 222795 0 1782360 2184 0 16936 3076 0 0 0 0
 252       0 dm-0 31032 0 3624200 23924 0 0 0 0 0 23628 23924 0 0 0 0
 252       5 dm-5 1704 0 203008 2312 0 0 0 0 0 2128 2312 0 0 0 0

创建位置 block/genhd.c

其它：

/sys/block/dm-0 # ls
alignment_offset bdi capability dev discard_alignment dm ext_range holders inflight power queue range removable ro size slaves stat subsystem uevent

/sys/block/dm-0 # ls dm/
name rq_based_seq_io_merge_deadline suspended use_blk_mq uuid

/sys/block/dm-0 # ls queue
add_random          discard_max_bytes    io_poll            max_discard_segments   max_segment_size nr_requests         rotational   write_cache
chunk_sectors       discard_max_hw_bytes io_poll_delay      max_hw_sectors_kb      max_segments     optimal_io_size     rq_affinity  write_same_max_bytes
dax                 discard_zeroes_data  iostats            max_integrity_segments minimum_io_size  physical_block_size scheduler    write_zeroes_max_bytes
discard_granularity hw_sector_size       logical_block_size max_sectors_kb         nomerges         read_ahead_kb       wbt_lat_usec zoned

 

二、命令

1. df

/ # df
Filesystem             1K-blocks    Used Available Use% Mounted on
tmpfs                    6941652    1644   6940008   1% /dev
tmpfs                    6941652       0   6941652   0% /mnt
/dev/block/dm-5           324420  324420         0 100% /vendor
/dev/block/persist         27632     204     27428   1% /mnt/vendor/persist
/dev/block/bluetooth_a     65488     864     64624   2% /vendor/bt_firmware
/dev/fuse               96464524 5509204  90955320   6% /mnt/user/10/emulated
...