ORA-27077: too many files open error in Oracle 7 Operating system

Error:
We are getting the following error in Oracle alert log file having Oracle 7 Operating system.

ORA-15025: could not open disk "/dev/mapper/asm06"
ORA-27077: too many files open
2017-12-02T17:12:39.028419-05:00
WARNING: Write Failed. group:2 disk:4 AU:96410 offset:0 size:253952
path:Unknown disk
incarnation:0xf8875997 asynchronous result:'I/O error'
subsys:Unknown library krq:0x7fbc2804b440 bufp:0x7fbc45dd1000 osderr1:0x434c5344 osderr2:0x0
IO elapsed time: 0 usec Time waited on I/O: 0 usec

Other similar error:
ORA-27301: OS failure message: Too many open files in system


Cause
kernel parameter fs.file-max value is set too small.

Solution:
1. Check the value of parameter “fs.file-max” in file etc/sysctl.conf

2. Increase the value of this parameter “fs.file-max”.
Note: it value is calculated based on RAM size

Farmula: 4MB of RAM you need to set 256 open files value.

512 GB of RAM = 512*1024 = 524,288 MB
fs.file-max = (524288/4 ) * 256 = 8589934592
Then you need to set it to 8589934592


3. open the /etc/sysctl file and update the entry of parameter.

fs.file-max = 8589934592