Linux How to use, Tutorials and scripts; Guides

Linux Agent - Error - Replication Driver Missing If any policy fails in R1soft, then you need to click on the failed policy and check the field "Alerts". If you see error related to "hcpdriver module", like ============================ An exception occurred during the request. The replication driver was not detected (detail: An error occurred while loading the hcpdriver module, please check your system logs; Please run "r1soft-setup --get-module " on your Agent to install one. ). ============================ Then you need to make sure you have installed Kernel-devel & Kernel-headers on your "Agent Server". Run (On clients server); # lsmod | grep hcp If it returns no value, then the hcpdriver not running on your client machine. After that you need perform below steps, 1. Check the current running Kernel # uname -r 2. Check you installed correct Kernel-devel & Kernel-headers # rpm -qa | gre

Apache is modular in that you can add and remove features easily. Multi-Processing Modules (MPMs) provide this modular functionality at the core of Apache -- managing the network connections and dispatching the requests. MPMs let you use threads or even move Apache to a different operating system. Only one MPM can be active at one time, and it must be compiled in statically with  --with-mpm=(worker|prefork|event) . The traditional model of one process per request is called  prefork . A newer, threaded, model is called  worker , which uses multiple processes, each with multiple threads to get better performance with lower overhead. The final,  event MPM is a module that keeps separate pools of threads for different tasks. To determine which MPM you're currently using, execute  httpd -l Choosing the correct MPM to use depends on many factors. On the surface, threading sounds better than forking, if all the underlying modules are thread safe, including all the libraries used

1) Save the current Firewall rules to some file. (In case something goes wrong we can quickly revert the settings. # iptables-save > /tmp/iptables.bkup 2) Now edit the file /tmp/iptables and copy paste the below command for making the port public. # iptables -A INPUT -p tcp -m state --state NEW -m tcp --dport 443 -j ACCEPT 3) The below command will write the new changes of iptables into the memory. # iptables-restore < /tmp/iptables.bkup 4) The below command will make the firewall changes permanent. After reboot also the new changes will not be lost. # /etc/init.d/iptables save 5) Alternatively we can issue the below commands for making the ports public through terminal and we can save the iptables rules. # iptables -I INPUT -p tcp -m tcp --dport 443 -j ACCEPT # iptables -I INPUT -p tcp -m tcp --dport 3306 -j ACCEPT

MaxKeepAliveRequests MaxKeepAliveRequests limits the number of requests allowed per connection. It is used to control persistent connections. In Ubuntu, the default value of  MaxKeepAliveRequests  is  100 . You can change it to any value you desire. The recommended value of  MaxKeepAliveRequests  is between 50 and 75. You can change this value by editing the Apache configuration file. sudo nano / etc / httpd / httpd.conf Change the value from 100 to 60. MaxKeepAliveRequests 60 Save the file and restart Apache. sudo / etc / init.d / httpd restart KeepAliveTimeout KeepAliveTimeout defines how long the server waits for the new request from connected clients. Setting KeepAliveTimeout to a high value may cause performance issues in a heavily loaded web server. In Ubuntu, the default value of  KeepAliveTimeout  is  15 . The recommended value of  KeepAliveTimeout  is between 1 and 5. You can change this value by editing the Apache configuration file. sudo nano /

1.     To generate an RSA key pair to work with version 2 of the protocol, type the following command at a shell prompt: 2.   ssh-keygen -t rsa [pravesh@localhost ~]$ ssh-keygen -t rsa Generating public/private rsa key pair. Enter file in which to save the key (/home/pravesh/.ssh/id_rsa): pravesh Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in pravesh. Your public key has been saved in pravesh.pub. The key fingerprint is: ed:5e:fb:5d:87:a2:12:ac:5d:98:1c:59:df:e3:81:1a pravesh@localhost.localdomain The key's randomart image is: +--[ RSA 2048]----+ |                 | |          .      | |         o . o   | |        o.E o +  | |       oS+.o . o | |        *.o   .. | |       o o. o . o| |      . o. o o .o| |         .o ... .| +-----------------+ [pravesh@localhost ~]$ ls -la total 28 -rw-------  1 pravesh pravesh 1743 Apr 29 14:30 pravesh -rw-r--r--  1 pravesh pravesh