mount

 

remount /

if (: > /.testrw) > /dev/null >&1; then
  rm -f /.testrw
else
  mount -o remount,rw / || echo 'Failed mount / rw'
fi

 

mount pseudo fs

1. /proc
   

   mount -n -t proc -o rw,nosuid,nodev,noexec,relatime proc /proc

    

2. /sys
   

   mount -n -t sysfs -o rw,nosuid,nodev,noexec,relatime sysfs /sys

    

3. /dev
   

   mount -n -t devtmpfs -o rw,nosuid,size=4096k,nr_inodes=1048576,mode=755,inodes64 devtmpfs /dev

    

4. /dev/shm
   

   mount -o remount,size=8G /dev/shm
   
   mount -t tmpfs -o size=5G,nr_inodes=5K,mode=700 tmpfs /mnt/tmpfs

    

restrict modify the size of /dev/shm

add below into /etc/fstab

none /dev/shm tmpfs defaults,size=1G 0 0

Take effect immediately: mount -av or mount -o remount /dev/shm