Yesterday I wrote about increasing local port range with net.ipv4.ip_local_port_range proc file. There is also /proc/sys/kernel/pid_max file, which specifies the value at which PIDs wrap around (i.e., the value in this file is one greater than the maximum PID). The default value for this file, 32768, results in the same range of PIDs as on earlier kernels (<=2.4). The value in this file can be set to any value up to 2^22 (PID_MAX_LIMIT, approximately 4 million).
Increasing the value will help on large Linux system or clusters to ease process identification and process management. You can easily prevent fork() failures error message with this hack.
Display Current Process Identifiers Limit
Type the following command at shell prompt:
$ sysctl kernel.pid_max
OR
$ cat /proc/sys/kernel/pid_max
Output:
kernel.pid_max = 32768
Allow for more PIDs
Type the following command
# sysctl -w kernel.pid_max=4194303
You need to append the following to your /etc/sysctl.conf:
kernel.pid_max = 4194303
Please note that this hack is only useful for large and busy server, don't try this on old kernel or desktop systems.
You should follow me on twitter here or grab rss feed to keep track of new changes.
Featured Articles:
- 30 Handy Bash Shell Aliases For Linux / Unix / Mac OS X
- Top 30 Nmap Command Examples For Sys/Network Admins
- 25 PHP Security Best Practices For Sys Admins
- 20 Linux System Monitoring Tools Every SysAdmin Should Know
- 20 Linux Server Hardening Security Tips
- Linux: 20 Iptables Examples For New SysAdmins
- Top 20 OpenSSH Server Best Security Practices
- Top 20 Nginx WebServer Best Security Practices
- 20 Examples: Make Sure Unix / Linux Configuration Files Are Free From Syntax Errors
- 15 Greatest Open Source Terminal Applications Of 2012

- My 10 UNIX Command Line Mistakes
- Top 10 Open Source Web-Based Project Management Software
- Top 5 Email Client For Linux, Mac OS X, and Windows Users
- The Novice Guide To Buying A Linux Laptop












{ 0 comments… add one now }