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0
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1answer
39 views

/etc/sysctl.conf Fedora {17-20}? [SOLVED]

Since Fedora 16 or 17 there no longer file /etc/sysctl.conf. How do I setup net.ipv4.ip_forward = 1?
2
votes
1answer
50 views

What is the difference between all and default in kernel setting? [duplicate]

I want to enable reversed path filtering to prevent source ip spoofing on my server. I noticed that I have the following settings at current: net.ipv4.conf.all.rp_filter = 0 ...
1
vote
1answer
42 views

How to undo kernel settings?

While trying to read some kernel parameters, I think I have mistakenly set some instead: # sysctl --system -r ^net.*tcp * Applying /usr/lib/sysctl.d/00-system.conf ... * Applying ...
1
vote
1answer
54 views

Sysctl parameter change after every reboot

I have found that the value of net.netfilter.nf_conntrack_count variable change every time i reboot the system. Did any one have an explanation for that?
0
votes
1answer
64 views

Get a faster response for a ping

I noticed that the answer to my ping is slower in one debian machine that another. For the first one when i ping to 8.8.8.8: 64 bytes from 8.8.8.8: icmp_req=1 ttl=47 time=29.6 ms For the second ...
0
votes
1answer
57 views

Change network values from sysctl.conf

Can I change the value of those parameters (spoofprotect, syncookies, dynaddr_hack, notimestamps, nobroadcasticmpecho, ip_forward) from sysctl.conf file in systemd?
1
vote
1answer
50 views

Change sysctl parameters for all interfaces

How can i change a parameter for all interfaces in systemd ? For example: sysctl -w "net.ipv4.conf.eth0.rp_filter=0" sysctl -w "net.ipv4.conf.eth1.rp_filter=0" How can change it for all ...
1
vote
1answer
127 views

What's the right way to set Linux kernel runtime parameters?

What's the prescribed way to set Linux kernel runtime parameters? I've seen sometimes that people will set these in files such as /etc/rc.local. Is this really the right way to do this?
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votes
3answers
4k views

How to persist ulimit settings in OSX Mavericks?

Before Mavericks, one could use /etc/launchd.conf to persist ulimit settings, for example: limit maxfiles 16384 unlimited limit maxproc 16384 unlimited It no longer works in Mavericks. What is the ...
2
votes
1answer
410 views

Error: permission denied on key 'fs.file-nr'

# sysctl -w fs.file-nr=131072 error: permission denied on key 'fs.file-nr' Same issue when I edit /etc/sysctl.conf and try sysctl -p. Any reason why I cannot edit this value? I am on CentOS 6.5
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votes
1answer
7k views

disable transparent hugepages

We are installing SAP HANA in a RAID machine. As part of the installation step, it is mentioned that, To disable the usage of transparent hugepages set the kernel settings at runtime with echo ...
10
votes
1answer
868 views

sysctl: /proc/sys/net/ipv[46]/conf/: what's the difference between “all”, “default” and “eth*”?

In sysctl, the /proc/sys/net/ipv[46]/conf/ keys have the following subkeys: all, default, and a key for each network interface. For example, on a machine with a single network interface eth0, it will ...
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votes
2answers
688 views

/proc/sys vs /sys/modules/mod/parameter

I've been wondering for last few days how exactly does it work. We can set kernel runtimes parameters using sysctl or echo boolen 1> /proc/sys/module/exactParameter but in ...
3
votes
1answer
597 views

Benchmarking Apache using ab

I was doing some performance testing for Apache using ab. Apache in our case is only working as a load balancer balancing load between two Liferay servers. Initially, I did the testing for 1000 ...
2
votes
0answers
158 views

Unable to reduce core frequency freebsd

I'm working on a FreeBSD project where I need to maintain the temperature of the processor below a threshold value. In order to reduce the temperature I'm trying to dynamically change the frequency of ...
2
votes
2answers
859 views

Finding out the values of kernel options related to sysctl.conf and sysctl.d

On my Ubuntu machine, in /etc/sysctl.conf file, I've got reverse path filtering options commented out by default like this: #net.ipv4.conf.default.rp_filter=1 #net.ipv4.conf.all.rp_filter=1 but in ...
6
votes
2answers
2k views

Find out sysctl default values? (without rebooting)

I have modified the value of net.core.rmem_max with sysctl, and now I would like to set it back to its default value. If I reboot, net.core.rmem_max will go back to its default value (because it is ...
2
votes
1answer
2k views

sysctl parameter for correct ARP response

I have a server that has some VMs, but the VMs can't communicate properly with the server because the server has several interfaces, and it responds on the wrong one. Q: We know that there is a ...
42
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5answers
20k views

Can I configure my Linux system for more aggressive file system caching?

I am neither concerned about RAM usage (as I've got enough) nor about losing data in case of an accidental shut-down (as my power is backed, the system is reliable and the data are not critical). But ...
2
votes
1answer
545 views

Puppet problem with sysctl

Running CentOS 5.5 with Puppet 0.25.5 I have installed and am using the puppet-sysctl module. However the following error occurs: //linux_tuning/Sysctl::Value[net.core.rmem_default] ...
8
votes
1answer
5k views

Description of kernel.printk values

Between Debian 5 and 6, the default suggested value for kernel.printk in /etc/sysctl.conf was changed from kernel.printk = 4 4 1 7 to kernel.printk = 3 4 1 3. I understand that the first value ...