Questions tagged [sysctl]
The sysctl tag has no usage guidance.
14
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linux + how to verify the dynamic ports allocation settings
How to know the range for the allocation of dynamic ports on red hat Linux machine
From Linux we did
sysctl -a | egrep "net.inet.ip.portrange.first|net.inet.ip.portrange.last"
but those ...
- 779
-1
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2
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68
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How to update Sysctl settings?
How to update Sysctl settings with
fs.inotify.max_user_watches=1048576
- 101
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168
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How to disable IPv6 on a logical/vlan/sub interface?
On Linux CentOS7, sysctl fails disabling IPv6 on a logical/vlan/sub interface :
$ ip -6 -o a show dev bond0.53
20: bond0.53 inet6 fe80::b283:feff:fee6:ba1/64 scope link \ valid_lft forever ...
- 1,601
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1
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kernel parameter - net.core.netdev_max_backlog , what happened when its too low
we want to understand what are the aspects when net.core.netdev_max_backlog kernel value is very low and not as recommended
on our Linux RHEL machines , the value for this parameter is 1000
since our ...
- 779
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39
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Sysctl kernel boot parameter not always applied fast enough for dependent processes
I'm running Debian on a custom Chromium OS (cros) kernel on a Chromebook. Cros kernel has disk-based swap file disabled by default (since it prefers zram), and to enable it sysctl variable vm....
- 31
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1
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86
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Low `threads-max` on a debian installation
I have two different debian 10 installations, both with 4core/8GB-RAM (name them A and B).
But the value of /proc/sys/kernel/threads-max is very different: A=63388 and B=7055.
The value of threads-max ...
- 249
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1
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136
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How to set sysctl fs.notify.max_user_watches in GUIX? (guix system: error: service 'sysctl' provided more than once)
IDE's like PyCharm work better when fs.inotify.max_user_watches is set to a high level. How to do that in GUIX?
I recall that the approach by Draketo used to work up to a few months ago: https://www....
- 587
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165
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How to allow only 100 half open SYN connections
I'm running Ubuntu and want to allow only 100 waiting SYN connections at a given time,
and drop the rest.
How can I configure iptables to implement this rule?
Or sysctl config to allow only 100, and ...
- 3
0
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0
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389
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High CPU load on SYN flood
When being under SYN flood attack, my CPU reach to 100% in no time by the kernel proccess named ksoftirqd,
I tried so many mitigations but none solve the problem.
This is my sysctl configurations ...
- 3
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votes
1
answer
435
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How do I set /sys/block/X/queue/scheduler on Ubuntu 18.04 with HWE on startup
I am running Ubuntu 18.04 (Bionic) with the HWE stack installed. This means I have the 5.3 Linux kernel running.
In older versions of the kernel, apparently passing elevator=noop when GRUB starts the ...
- 194
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1
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240
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Relationship of "ulimit -a" to fs.file-max
I am on an amazon linux ec2 instance and need to increase the files limit (to run spark).
It had been my recollection there were a way to do something like
ulimit -n 8192
But that is not "taking" ...
- 3,485
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0
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4k
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Permission denied when systemd-sysctl service starts and tries to write to file in /proc/sys/user/
I am trying to enable user namespaces on Docker. This of course requires user namespaces to be enabled in the kernel.
One of the steps to enable user namespaces in RHEL/CentOS is to:
echo "user....
- 11
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1
answer
575
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`sysctl` not available in script started by swanctl on NixOS
I use strongswan-swanctl on a VPN server running NixOS.
Basically it is working and I can connect to the VPN server from clients.
services.strongswan-swanctl = { ...
- 105
0
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1
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342
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IPV6: Ubiquiti Router, Ubuntu Client
I have a Ubiquiti router on which ipv6 appears to be working fine. The output of radvdump, along with various other relevant data, is below. My trouble is with ipv6 on an ubuntu 16.04 machine behind ...
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