IO 查看

gddg:~ # lsof /dev/xvda2 |head
COMMAND     PID       USER   FD   TYPE DEVICE SIZE/OFF   NODE NAME
init          1       root  cwd    DIR  202,240962 /
init          1       root  rtd    DIR  202,240962 /
init          1       root  txt    REG  202,240784193218 /sbin/init
init          1       root  mem    REG  202,2191148063 /lib64/libdl-2.11.1.so
init          1       root  mem    REG  202,216614548057 /lib64/libc-2.11.1.so
init          1       root  mem    REG  202,22363848114 /lib64/libsepol.so.1
init          1       root  mem    REG  202,21139048115 /lib64/libselinux.so.1
init          1       root  mem    REG  202,21497978050 /lib64/ld-2.11.1.so
kthreadd      2       root  cwd    DIR  202,240962 /

然后可以通过 lsof -p $pid 查看详情

gddg:~ # lsof -p 32597
COMMAND   PID USER   FD   TYPE DEVICE SIZE/OFF   NODE NAME
bash    32597 root  cwd    DIR  202,2409616097 /root
bash    32597 root  rtd    DIR  202,240962 /
bash    32597 root  txt    REG  202,258401632203 /bin/bash
bash    32597 root  mem    REG  202,22939368125 /lib64/libncurses.so.5.6
bash    32597 root  mem    REG  202,216614548057 /lib64/libc-2.11.1.so
bash    32597 root  mem    REG  202,2191148063 /lib64/libdl-2.11.1.so
bash    32597 root  mem    REG  202,22635688153 /lib64/libreadline.so.5.2
bash    32597 root  mem    REG  202,21497978050 /lib64/ld-2.11.1.so
bash    32597 root  mem    REG  202,221701616498 /var/run/nscd/passwd
bash    32597 root  mem    REG  202,2256324149503 /usr/lib/locale/en_US.utf8/LC_CTYPE
bash    32597 root  mem    REG  202,254149490 /usr/lib/locale/en_US.utf8/LC_NUMERIC
bash    32597 root  mem    REG  202,22454133112 /usr/lib/locale/en_US.utf8/LC_TIME
bash    32597 root  mem    REG  202,21163682149504 /usr/lib/locale/en_US.utf8/LC_COLLATE
bash    32597 root  mem    REG  202,2286133111 /usr/lib/locale/en_US.utf8/LC_MONETARY
bash    32597 root  mem    REG  202,257149408 /usr/lib/locale/en_US.utf8/LC_MESSAGES/SYS_LC_MESSAGES
bash    32597 root  mem    REG  202,234149428 /usr/lib/locale/en_US.utf8/LC_PAPER
bash    32597 root  mem    REG  202,277149438 /usr/lib/locale/en_US.utf8/LC_NAME
bash    32597 root  mem    REG  202,2155133108 /usr/lib/locale/en_US.utf8/LC_ADDRESS
bash    32597 root  mem    REG  202,259149407 /usr/lib/locale/en_US.utf8/LC_TELEPHONE
bash    32597 root  mem    REG  202,223149429 /usr/lib/locale/en_US.utf8/LC_MEASUREMENT
bash    32597 root  mem    REG  202,226050149293 /usr/lib64/gconv/gconv-modules.cache

2. cat /proc/$pid/io

如果内核版本大于2.6.20，通过cat /proc/pid/io 便可以获取进程的io信息。详细解释

gddg:~ # cat /proc/4140/io
rchar: 197448798054// 读出的总字节数，read()或者pread()中的长度参数总和(pagecache中统计而来，不代表实际磁盘的读入)
wchar: 209896059897// 写入的总字节数，write()或者pwrite()中的长度参数总和
syscr: 6491904// read()或者pread()总的调用次数
syscw: 13633940// write()或者pwrite()总的调用次数
read_bytes: 49616125952// 实际从磁盘中读取的字节总数
write_bytes: 14038130688// 实际写入到磁盘中的字节总数
cancelled_write_bytes: 2473984// 由于截断pagecache导致应该发生而没有发生的写入字节数

3. block_dump

通过echo 1 > /proc/sys/vm/block_dump ，来把 block 读写（WRITE/READ/DIRTY）状况 dump 到日志里，通过 dmesg 命令来查看