All the files under /proc is viewed by the cat vi command.
/proc/<PID> it contain the information about the running process – used command ps, top
Example if you run the httpd service it has 2843 process id these directory located in the /proc/2843
/proc/cpuinfo it contains the information about regarding CPU related.
/prc/mdstat it contain the information about RAID about md device – mdadm
/proc/meminfo , /proc/swaps– it contain the information about memory usage – free vmstat
/proc/modules have the list of modules it can be view by the lsmod command.
/proc/mounts contain the mounted file system information – mount
/proc/partitions have partition info
/proc/net contain the information about networking Informaiton – ifconfig ,netstat
/proc/version Linux kernel version uname –v
/proc/sys/kernel/hostname system hostname
/proc/sys/net/ipv4/ip_forward IP forwarding on or off
File system Information
To Change the Proc Kernel Entries
#echo 2> /proc/sys/vm/drop_caches. [clear PAGECACHE, DENTRIES, and INODES ]
#echo 1 > /proc/sys/net/ipv4/ip_forward [ To ENABLE IP Forwarding]
(or) net.ipv4.ip_forward = 1 Line into /etc/sysctl.conf