June 28, 2021 in Tips and Tricks, Ubuntu
Goto /var/log diretcory
$ cd /var/log
List files and directories date wise descending order
$ ls -altls by date in reverse date order use the -t flag as before but this time with the -r flag which is for ‘reverse’.
June 28, 2021 in Technology, Tips and Tricks, Ubuntu
System Load or System Load Average
It is run-queue i.e a queue of processes waiting for a resource(cpu, i/o etc.) to become available .
Consider a single-core cpu as a single lane of traffic with bridge and process as cars.
Now in this situation System load is
This number is not normalized according to your cpu. In Multiprocessor system, load 2 mean 100 % utilization of we are using dual-core processor, load 4 means 100% utilization if we are using quad-core.
You can get your system load using
uptimecat /proc/loadavgtop$uptime 22:49:47 up 11:47, 4 users, load average: 2.20, 1.03, 0.82Here the last three number representing the system load average for 1, 5 and 15 minutes respectively.
The example above indicates that on average there were 2.20 processes waiting to be scheduled on the run-queue measured over the last minute.
June 28, 2021 in Tips and Tricks, Ubuntu
This works very well:
while true; do uptime >> uptime.log; sleep 1; done
uptime.log.You can then import this file into Gnumeric or the OpenOffice spreadsheet to create a nice graph (select ‘separated by spaces’ on import).As Scaine noticed, this won’t be enough to diagnose the problem. So, additionally, run this (or use his answer for this part):
while true; do (echo "%CPU %MEM ARGS $(date)" && ps -e -o pcpu,pmem,args --sort=pcpu | cut -d" " -f1-5 | tail) >> ps.log; sleep 5; done
ps.log every five seconds.Note that this is not the full boat-load of information top would give you. This is just the top 10, and just their CPU Usage, Memory Usage and the first argument (i.e. their command without further arguments, as in /usr/bin/firefox)After you’ve used a Spreadsheet to create a graph to see when your CPU load went through the roof, you can then search this file for the nearest time to see what process has caused it.
This is what those files will look like:
uptime.log
~$ cat uptime.log
22:57:42 up 1 day, 4:38, 4 users, load average: 1.00, 1.26, 1.21
22:57:43 up 1 day, 4:38, 4 users, load average: 0.92, 1.24, 1.21
22:57:44 up 1 day, 4:38, 4 users, load average: 0.92, 1.24, 1.21
22:57:45 up 1 day, 4:38, 4 users, load average: 0.92, 1.24, 1.21
...
ps.log
%CPU %MEM ARGS Mo 17. Jan 23:09:47 CET 2011
0.7 0.9 /usr/bin/compiz
0.8 0.5 /usr/lib/gnome-panel/clock-applet
1.1 1.7 /opt/google/chrome/chrome
1.2 0.3 /usr/bin/pulseaudio
1.8 4.0 /opt/google/chrome/chrome
2.6 1.5 /opt/google/chrome/chrome
2.6 3.2 /usr/bin/google-chrome
3.6 2.6 /opt/google/chrome/chrome
4.9 1.5 /usr/bin/X
5.7 1.6 /opt/google/chrome/chrome
%CPU %MEM ARGS Mo 17. Jan 23:09:48 CET 2011
0.7 0.9 /usr/bin/compiz
0.8 0.5 /usr/lib/gnome-panel/clock-applet
1.0 1.7 /opt/google/chrome/chrome
1.2 0.3 /usr/bin/pulseaudio
1.8 4.0 /opt/google/chrome/chrome
2.6 1.5 /opt/google/chrome/chrome
2.6 3.2 /usr/bin/google-chrome
3.6 2.6 /opt/google/chrome/chrome
4.9 1.5 /usr/bin/X
5.7 1.6 /opt/google/chrome/chrome
...April 16, 2021 in News, Ubuntu
remove sendmail ubuntu
$ sudo apt-get purge sendmail*
$ apt-get remove sendmail
$ apt-get purge sendmailremove postfix ubuntu
$ sudo apt remove postfix && apt purge postfix
$ sudo autoremoveWhen I install Postfix again, the installation does not ask the questions like on the first installation. I still have my previous configuration. Why can not I reset the Postfix configuration ?
If I reconfigure Postfix, I still have the previous configuration :
$ sudo dpkg-reconfigure postfixremove mailutils ubuntu
$ sudo apt-get remove mailutils
$ sudo apt-get remove --auto-remove mailutils
$ sudo apt-get purge mailutils
$ sudo apt-get purge --auto-remove mailutilsApril 16, 2021 in Tips and Tricks, Ubuntu
By default, any email sent by system is sent to root@hostname. So critical server errors, log errors, corn jobs alerts e.t.c all are sent to this default email address. To change it to different appropriate email id, we can do this by two ways.
For this example, lets set email to system@mydomain.com
Step 1 : edit /etc/aliases file
$ vi /etc/aliases
Add email ids at the bottom of the file.
postmaster: system@mydmomain.com
To add multiple email ids, we can simply separate them by comma.
postmaster: system@mydomain.com, linux@mydomain.com
linux@mydomain.com is second email id
Step 2: Run the aliases command, to compile aliases file.
$ newaliases
Step 3: Restart postfix server.
service postfix restart
We can simply create .forward file to the folder root and add email address there.
$ vi /root/.forward
system@mydomain.com Restart postfix server
$ service postfix restart.
April 15, 2021 in Php, Tips and Tricks, Ubuntu
How to change phpmyadmin url of ubuntu aws server
http://www.domain.in/dbaditya/
this is the url
in this video we change dbaditya to newname
Note: top command to show process monitor of server
q used for quit from top command window/screen
http://www.domain.in/mynewdata/
Done URL succcessfully changed
January 23, 2021 in Tips and Tricks, Ubuntu
sudo leafpad /etc/lxdm/default.conf
sudo leafpad /etc/lightdm/fileexample.confIn the fist few line, you will see something like autologin=username change it to the original state of # autologin=dgod. Save the file, and then reboot your machine.
autologin-user=username
autologin-user-timeout=0Using privileged admin account open up terminal or your favorite text file editor and edit the /etc/gdm3/custom.conf configuration file. Change from:
[daemon]
# Uncoment the line below to force the login screen to use Xorg
#WaylandEnable=false
# Enabling automatic login
# AutomaticLoginEnable = true
# AutomaticLogin = user1December 21, 2020 in Php, Tips and Tricks, Ubuntu
I want to enable the simple php mail() function on an Ubuntu server.
three steps
sudo apt-get install sendmail
sudo sendmailconfig (answer Yes to everything)
sudo service apache2 restartOctober 26, 2020 in Tips and Tricks, Ubuntu
GNU Wget is a command-line utility for downloading files from the web. With Wget, you can download files using HTTP, HTTPS, and FTP protocols. Wget provides a number of options allowing you to download multiple files, resume downloads, limit the bandwidth, recursive downloads, download in the background, mirror a website and much more.
sudo apt install wgetsudo yum install wgetThe wget utility expressions take the following form:
$ wget [options] [url]
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options – The Wget optionsurl – URL of the file or directory you want to download or synchronize.In it’s simplest form when used without any option, wget will download the resource specified in the [url] to the current directory.
In the following example we are downloading the Linux kernel tar archive:
$ wget https://cdn.kernel.org/pub/linux/kernel/v4.x/linux-4.17.2.tar.xzTo save the downloaded file under a different name, pass the -O option followed by the chosen name:
$ wget -O latest-hugo.zip https://github.com/gohugoio/hugo/archive/master.zipThe command above will save the latest hugo zip file from GitHub as latest-hugo.zip instead of its original name.
By default, Wget will save the downloaded file in the current working directory. To save the file to a specific location, use the -P option:
$ wget -P /mnt/iso http://mirrors.mit.edu/centos/7/isos/x86_64/CentOS-7-x86_64-Minimal-1804.isoTo limit the download speed, use the --limit-rate option. By default, the speed is measured in bytes/second. Append k for kilobytes , m for megabytes and g for gigabytes.
The following command will download the Go binary and limit the download speed to 1mb:
$ wget --limit-rate=1m https://dl.google.com/go/go1.10.3.linux-amd64.tar.gzThis option is useful when you don’t want wget to consume all the available bandwidth.
You can resume a download using the -c option. This is useful if your connection drops during a download of a large file, and instead of starting the download from scratch, you can continue the previous one.
In the following example we are resuming the download of the Ubuntu 18.04 iso file:
$ wget -c http://releases.ubuntu.com/18.04/ubuntu-18.04-live-server-amd64.isoIf the remote server does not support resuming downloads, Wget will start the download from the beginning and overwrite the existing file.
To download in the background ,use the -b option. In the following example, we are downloading the OpenSuse iso file in the background:
$ wget -b https://download.opensuse.org/tumbleweed/iso/openSUSE-Tumbleweed-DVD-x86_64-Current.isoBy default, the output is redirected to wget-log file in the current directory. To watch the status of the download, use the tail command:
$ tail -f wget-logSometimes when downloading a file, the remote server may be set to block the Wget User-Agent. In situations like this to emulate a different browser pass the -U option.
wget --user-agent="Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0" http://wget-forbidden.com/The command above will emulate Firefox 60 requesting the page from wget-forbidden.com
If you want to download multiple files at once, use the -i option followed by the path to a local or external file containing a list of the URLs to be downloaded. Each URL needs to be on a separate line.
In the following example we are downloading the Arch Linux, Debian, and Fedora iso files with URLs specified in the linux-distros.txt file:
$ wget -i linux-distros.txtlinux-distros.txt
http://mirrors.edge.kernel.org/archlinux/iso/2018.06.01/archlinux-2018.06.01-x86_64.iso
https://cdimage.debian.org/debian-cd/current/amd64/iso-cd/debian-9.4.0-amd64-netinst.iso
https://download.fedoraproject.org/pub/fedora/linux/releases/28/Server/x86_64/iso/Fedora-Server-dvd-x86_64-28-1.1.iso
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If you specify - as a filename, URLs will be read from the standard input.
To download a file from a password-protected FTP server, specify the username and password as shown below:
$ wget --ftp-user=FTP_USERNAME --ftp-password=FTP_PASSWORD ftp://ftp.example.com/filename.tar.gzTo create a mirror of a website with Wget, use the -m option. This will create a complete local copy of the website by following and downloading all internal links as well as the website resources (JavaScript, CSS, Images).
$ wget -m https://example.comIf you want to use the downloaded website for local browsing, you will need to pass a few extra arguments to the command above.
$ wget -m -k -p https://example.comThe -k option will cause Wget to convert the links in the downloaded documents to make them suitable for local viewing. The -p option will tell wget to download all necessary files for displaying the HTML page.
If you want to download a file over HTTPS from a host that has an invalid SSL certificate, use the --no-check-certificate option:
$ wget --no-check-certificate https://domain-with-invalid-ss.comIn the following example, Wget will quietly ( flag -q) download and output the latest WordPress version to stdout ( flag -O -) and pipe it to the tar utility which will extract the archive to the /var/www directory.
$ wget -q -O - "http://wordpress.org/latest.tar.gz" | tar -xzf - -C /var/wwwOctober 26, 2020 in MySql, Tips and Tricks, Ubuntu
Log in a MySQL root user:
$ mysql -u user -pRun the SHOW DATABASES command:
mysql> SHOW DATABASES;EXPORT from MySql
$ mysqldump -u [username] -p [database name] > [database name].sql
IMPORT in MySql
$ mysql -u [username] -p newdatabase < [database name].sql
