syncookies cookies the connection state,when the ack arrives,then deal with the pause connection,very wise mind --------------------------------------------------------------------------- seems to be enough -------------------------------------------…

Kernel parameter requirements ( Linux DB2) https://www.ibm.com/support/knowledgecenter/SSEPGG_9.7.0/com.ibm.db2.luw.qb.server.doc/doc/c0057140.html You must have root authority to modify kernel parameters. Run the ipcs -l command to list the current…

Android 8.0 在frida中使用 -f 参数报错, Error message: Failed to spawn: unable to access process with pid 413 due to system restrictions; try `sudo sysctl kernel.yama.ptrace_scope=0`, or run Frida as root 通过ps -A  413 查看进程,发现为zygote64,冲突的原因是Magisk  开启了Magisk…

现在CPU2核以上比较普遍了,平时用linux上上网可能用不着双核甚至4核,大部分发行版内核都启用了CPU_HOTPLUG,到/sys/devices/system/cpu下可以看到文件夹cpu0.cpu1,除cpu0(这个不能关)每个文件夹下都有一个online文件,往里面写0就可以关闭核心,比如我的T7300,echo '0' >/sys/devices/system/cpu/cpu1/online 就可以关闭第二个核,不影响小型应用.要开启,往里面echo 1就行.这个操作好像要root完…

我刚刚开始学习Python, Python中的参数传递总是让我很困惑.我写了4个简单的Demo,帮助我理解Python的参数传递,希望对大家都能有所帮助. 0: def change(x): x = 1 a = 10print('a is {0}'.format(a)) change(a) print('a is {0}'.format(a)) Output:a is 10a is 10 1: def change1(x): x = [1, 2] a = [10, 20]print('a is…

安装Oracle11g内核参数semopm未校验通过,点击Fix&Check Again后,会提示执行修改脚本,在/tmp/CVU_11.2.0.1.0_oracle下,找到并执行该脚本runfixup.sh后.检验通过.…

Symptom You have questions related to the SAP HANA memory. You experience a high memory utilization or out of memory dumps. Environment SAP HANA Cause 1. Which indications exist for SAP HANA memory problems?2. How can I collect information about the…

procps包里面的sysctl命令 --http://www.cnblogs.com/createyuan/p/3740917.html?utm_source=tuicool&utm_medium=referral 概述 [root@localhost ~]# rpm -qf /sbin/sysctlprocps-3.2.8-25.el6.x86_64 我们常常在 Linux 的 /proc/sys 目录下,手动设定一些 kernel 的参数或是直接 echo 特定的值给一个 proc下的文件…

ipcs.ipcrm.sysresv.kernel.shmmax 1.1  BLOG文档结构图 1.2  前言部分 1.2.1  导读和注意事项 各位技术爱好者,看完本文后,你可以掌握如下的技能,也可以学到一些其它你所不知道的知识,~O(∩_∩)O~: ① ipcs的使用 ② ipcrm释放oracle内存段 ③ sysresv的使用 ④ 内核参数kernel.shmmax ⑤ 如何快速的清理Oracle的进程 ⑥ 其它维护操作   Tips: ① 本文在itpub(http://blog.it…

参考资料: <ARM体系结构与编程> <嵌入式Linux应用开发完全手册> Linux_Memory_Address_Mapping http://www.chinaunix.net/old_jh/4/1021226.html 更多文档参见:http://pan.baidu.com/s/1mg3DbHQ 本文针对arm linux, 从kernel的第一条指令开始分析,一直分析到进入start_kernel()函数. 我们当前以linux-2.6.19内核版本作为范例来分析,本文中…

This post builds on a previous post, but can be read and understood independently. As part of my course on statistical learning, we created 3D graphics to foster a more intuitive understanding of the various methods that are used to relax the assumpt…

Db2 11.1 For root installations, the database manager uses a formula to automatically adjust kernel parameter settings and eliminate the need for manual updates to these settings. Before you begin You must have root authority to modify kernel paramet…

内核 linux内核是单内核体系设计.但充分借鉴了微内核设计体系的优点,为内核引入模块化机制 内核组成部分: kernel: 内核核心,一般为bzImage,通常在/boot 目录下,名称为vmlinuz-VERSION-RELEASE. kernel object: 内核对象,一般放置于/lib/modules/VERSION-RELEASE/ 辅助文件: ramdisk initrd initramfs 内核版本 运行中的内核: uname 命令: uname - print system…

http://blog.lifeibo.com/?p=380 1.sysctl sysctl命令被用于在内核运行时动态地修改内核的运行参数,可用的内核参数在目录/proc/sys中 [root@server1 ~]# cd /proc/sys[root@server1 sys]# ll总用量 0dr-xr-xr-x 0 root root 0 6月 5 20:59 abidr-xr-xr-x 0 root root 0 6月 5 20:59 cryptodr-xr-xr-x 0 root roo…

# sysctl kernel.pid_max kernel.pid_max = # sysctl - kernel.pid_max = #include <unistd.h> #include <stdio.h> int main () { pid_t fpid; //fpid表示fork函数返回的值 ; ) { fpid=fork(); ) { printf("error in fork!\n"); break; } ) { count++; } else…

http://blog.kreyolys.com/2011/03/17/no-panic-its-just-a-kernel-panic/ One of the main young sysadmin fear is to being asked by management to find out the root cause of a system crash or hang! When realizing that there are no error messages in the log…

The Core Issues and Ideas of This Paper Problem Baseline Searchable Symmetric Encryption (SSE) could not avoid access-pattern leakage. ORAM algorithm performance is extremely low and cannot be applied in practice. Idea Solve the Access-pattern Leakag…

指定--sysctl参数来设置系统参数,通过这些参数来调整系统性能,Docker通过一个 ValidateSysctl函数来限制 sysctl参数可以传入的项,源码如下: // docker/opts/opts.go func ValidateSysctl(val string) (string, error) { validSysctlMap := map[string]bool{ "kernel.msgmax": true, "kernel.msgmnb": t…

0x01漏洞简介: 3月31日, 选手Manfred Paul 在Pwn2Own比赛上用于演示Linux内核权限提升的漏洞被CVE收录,漏洞编号为CVE-2020-8835.此漏洞由于bpf验证系统在Linux内核中没有正确计算某些操作的寄存器限制,导致本地攻击者可以利用此缺陷越界读取机密信息(内核内存)或将用户提升为管理权限.请相关用户采取措施进行防护. 0x02影响版本: ·Linux Kernel 5.4·Linux Kernel 5.5 0x03漏洞危害: 攻击者利用此漏洞,可实现信息获…

sysctl 命令用于查看和修改内核参数 查看指定参数: sysctl kernel.threads-max 查看所有参数: sysctl -a 修改指定参数: sysctl -w kernel.threds-max=102400 sysctl 设置的内核参数在 /proc/sys 目录下,格式为: 目录.文件 比如:kernel.threads-max  对应目录 /proc/sys/kernel 下的 threads-max 文件 sysctl 的配置文件是:/etc/sysctl.conf…

http://blog.packagecloud.io/eng/2016/06/22/monitoring-tuning-linux-networking-stack-receiving-data/ Jun 22, 2016 • packagecloud Tags: packagecloud linux kernel networking optimization tuning monitoring TL;DR This blog post explains how computers runn…

[root@localhost tt]# man listen LISTEN() Linux Programmer’s Manual LISTEN() NAME listen - listen for connections on a socket SYNOPSIS #include <sys/socket.h> int listen(int sockfd, int backlog); DESCRIPTION To accept connections, a socket ), a willi…

 Oracle Database (RDBMS) on Unix AIX,HP-UX,Linux,Mac OS X,Solaris,Tru64 Unix Operating Systems Installation and Configuration Requirements Quick Reference (8.0.5 to 11.2) (文档 ID 169706.1) _afrLoop=509703735454401&id=169706.1&_afrWindowMode=0&…

Oracle Real Application Clusters (RAC) databases form an increasing proportion of Oracle database systems. RAC was introduced in 2001 as part of Oracle 9i and was based on Oracle's earlier Oracle Parallel Server architecture. RAC is almost unique as…

Linux TCP Performance Tuning News Linux Performance Tuning Recommended Books Recommended Links Linux performance bottlenecks Kernel parameters tuning on Linux Performance Monitoring tcpdump iptraf netstat ntop nfsstat lsof vmstat Disk subsystem tunin…

Name ipsec.conf - IPsec configuration and connections Description The optional ipsec.conf file specifies most configuration and control information for the Openswan IPsec subsystem. (The major exception is secrets for authentication; seeipsec.secrets…

监控作业发现一台服务器(Red Hat Enterprise Linux Server release 5.7)从凌晨1:32开始,有一小段时间无法响应,数据库也连接不上,后面又正常了.早上检查了监听日志,并没有发现错误信息.但是检查告警日志,发现有下面错误信息: Thread 1 advanced to log sequence 19749 (LGWR switch)   Current log# 2 seq# 19749 mem# 0: /u01/oradata/epps/redo02.lo…

參考:1529864.1 ************************************************** RAM                                  Swap Space Between 1 GB and 2 GB       1.5 times the size of RAM Between 2 GB and 16 GB      Equal to the size of RAM More than 16 GB                …

Oracle EBS R12 (12.1.3) Installation Linux(64 bit) Contents Objective. 3 1 Download & Unzip. 3 Download. 3 Unzip. 3 MD5 Checksums. 4 2 Pre-Install Task. 5 Disk Space. 5 Specific Software Requirements. 5 RPM... 6 JDK. 8 OS User & Group. 11 3 Instal…

异步IO概念 Linux 异步 I/O (AIO)是 Linux 内核中提供的一个增强的功能.它是Linux 2.6 版本内核的一个标准特性,当然我们在2.4 版本内核的补丁中也可以找到它.AIO 背后的基本思想是允许进程发起很多 I/O 操作,而不用阻塞或等待任何操作完成.稍后或在接收到 I/O 操作完成的通知时,进程就可以检索 I/O 操作的结果. Linux IO模型(I/O models)分同步IO模型(synchronous models)和异步IO模型(asynchronous mo…