Example Operating System Tuning Values for Linux Master server running 7.x

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  • Article ID:000081370


Netbackup is designed to work with the default Linux operating system settings. For large environments, better performance can be found by tuning the operating system settings. The example values provided in this TechNote are for informational purposes and should be used as a reference tool only.

Every NetBackup environment is different. To get the most performance out of a NetBackup Master, Symantec recommends contacting Symantec Consulting Services to assist with an onsite health check and tuning changes as required.


Example Tuning Settings for a Master server handling >100 SAN Media servers and >1000 tape devices:

1 - Make changes to /proc/sys/kernel

- This setting is dynamic and no reboot is required. 
- This is good for testing settings but will not persist after reboot

echo 256 > /proc/sys/kernel/msgmni
echo 8192 > /proc/sys/kernel/msgmax
echo 65536 > /proc/sys/kernel/msgmnb
300 307200 64 1024 > /proc/sys/kernel/sem
echo "1" > /proc/sys/kernel/core_uses_pid
echo "/var/log/core.%e.%p" > /proc/sys/kernel/core_pattern

2 - /etc/sysctl.conf

- Changing settings here makes them persistent

kernel.sem = 300 307200 64 1024              
kernel.msgmni = 256
kernel.shmmni = 4096
kernel.core_pattern = /var/log/core.%e.%p

Check settings with:

>egrep "kernel.sem|kernel.msg|kernel.shm|core_p|core_u" /etc/sysctl.conf  
kernel.sem = 300 307200 32 1024             
kernel.msgmnb = 65536
kernel.msgmni = 256
kernel.msgmax = 65536
kernel.shmmni = 4096
kernel.shmall = 4294967296
kernel.shmmax = 68719476736
kernel.core_pattern = /var/log/core.%e.%p
kernel.core_uses_pid = 1

3 - /etc/security/limits.conf

add lines:

*               soft    core           unlimited
*               hard    core           unlimited
*               soft    nofile         8192
*               hard    nofile         63535

Making changes to /etc/security/limits.conf file does not change the ulimit values for the currently running NetBackup daemons if they were started by the init scripts in /etc/init.d. The ulimit changes will take affect once NetBackup daemons are restarted from the root shell.

4- /etc/pam.d/login

add line:

session    required     /lib/security/pam_limits.so

5 - /etc/profile

add line:

ulimit -S -c unlimited > /dev/null 2>&1 ulimit -aH

Confirm settings after login with:

>ulimit -aH

core file size          (blocks, -c) unlimited
data seg size           (kbytes, -d) unlimited
max nice                        (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 137215
max locked memory       (kbytes, -l) 32
max memory size         (kbytes, -m) unlimited
open files                      (-n) 63535
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
max rt priority                 (-r) 0
stack size              (kbytes, -s) unlimited
cpu time               (seconds, -t) unlimited
max user processes              (-u) 137215
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

See Also: 3rd party guide to tuning 10Gb network cards on Linux

Tuning 10Gb network cards on Linux



The settings provided in this document are an example of tuning values and are for reference use only. Caution is advised when modifying system and user tuning values as the changes may not be appropriate for your particular system. Always make a backup of any configuration files before making any changes.





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