BK Technophile

Install nc and pv $ sudo yum install pv Once you have nc and pv installed, it’s really simple. On one machine, run the following command: $ nc -ulp 5000 > /dev/null On the second machine run the following command (you need the IP address of the first machine): $ pv < /dev/zero | nc -u 192.168.0.174 5000 And you should get some output with a little <=> sign moving across the screen that resembles this (static): 1.15GB 0:00:19 [ 218MB/s] [ <=> ] This will show you the number of MB/s the connection is averaging; if you watch if for a bit, you can get an idea of where things stand. Here are some of the results I got between my RedHat, Fedora and Ubuntu Machines:

If you want report mtr -c 20 --report --no-dns destination_ip or mtr destnation ip

If you want incrase 2 GB of swap then follow below Steps dd if=/dev/zero of=/swapfile bs=1024 count=2097152 #mkswap /swapfile #swapon /swapfile #swapon -s check the swap file #cat /proc/swaps If you want parmanent then add line in fstab file #vi /etc/fstab /swapfile none swap sw 0 0 save the file and check with free commands #free

find the spaming domain and delete postqueue -p -c /etc/postfix |grep -i | cut -d ' ' -f 1 > /tmp/cleanoutqueue.sh cat /tmp/cleanoutqueue.sh |awk '{print "sudo postsuper -c /etc/postfix/ -d " $1}'> /tmp/cleanoutgo1.sh chmod +x /tmp/cleanoutgo1.sh sh /tmp/cleanoutgo1.sh

If you one hardisk crashed and you replaced that hard disk but hard disk not showing in order then follow the bellow steps:- #sudo fdisk /dev/sda At the fdisk command prompt: Enter m (for help) Next at the prompt: Enter x (extra functionality – experts only) f (fix) w (write to disk and exit) You may get a warning that devices are in use and the new table will be used at the next boot. If you want that the Linux Kernel reads the new partition table now , use the following command. sudo partprobe

Allowing ssh login using Sudo In order to record all the commands executed by a engineer when doing a remote login via ssh to your server do the following: 1. Login to the Linux server using the root login. 2. Edit the /etc/sudoers file using visudo. After editing the contents of the file shoud be as follows: # sudoers file. # # This file MUST be edited with the 'visudo' command as root. # # See the sudoers man page for the details on how to write a sudoers file. # # Host alias specification # User alias specification # Cmnd alias specification Cmnd_Alias USR_BIN_CMDS = /usr/bin/telnet, /usr/bin/tail, /usr/bin/diff, /usr/bin/dig, /usr/bin/find, \ /usr/bin/head, /usr/bin/kill, /usr/bin/ldapsearch, /usr/bin/man, \ /usr/bin/updatedb, /usr/bin/wget, /usr/bin/du, /usr/bin/watch Cmnd_Alias SBIN_CMDS = /sbin/chkconfig, /sbin/fdisk, /sbin/fsck, /sbin/ifconfig Cmnd_Alias USR_SBIN_CMDS = /usr/sbin/crond Cmnd_Alias USR_LIB_CMDS = /usr/lib/rpm