Archive

Articles taggués ‘commands’

Five reliable Windows Server backup solutions

13/01/2021 Aucun commentaire

When disaster strikes (and it will), you can put the pieces back together if you’ve got a solid backup solution in place.

If you have a Windows server and you’re not backing it up, you are tempting fate. It’s only a matter of time before something tragic will happen: a hardware failure, a hacker, or a corrupted Windows update. Something will bring that server down and do everything it can to take your data with it.

Luckily, several reliable backup solutions are available for the Windows Server environment. They aren’t perfect. But the five solutions discussed here have their strengths and can be depended upon to keep your data safe. Now, before I reveal the big five, I want to make sure you understand how critical it is to be backing up that data to an external drive and to rotate that drive offsite. If you’re backing up drives and leaving everything onsite, should a fire (or some other catastrophe) occur, that data will be lost.

Note: This list is also available as a photo gallery.

1: Acronis Backup and Restore (with Universal Restore)

Acronis Backup and Restore (Figure A) is the backup tool I use the most. It’s costly but well worth it. The newer version of Acronis does a great job of ensuring that there is room on your external drive for your latest backup. You can overwrite the old backup or go by the traditional cleanup rules established in Acronis Echo. But if you go the Acronis route, you should also purchase the Universal Restore feature. With this tool, you can take a full image of a backup and restore it to any hardware — so long as it meets the requirements of your platform. That way, you don’t need an exact duplicate of your server hardware sitting around waiting to have an image restored onto it. Acronis also has add-ons for Exchange and SQL Servers.

Figure A

 

Acronis backup
Acronis Backup and Restore

2: Symantec Backup Exec

Symantec Backup Exec (Figure B) is a powerful backup solution that does a great job of “just working.” And with its at-a-glance calendar, it’s easy to know when your backup has succeeded and when it has worked. If you’re using Symantec Backup Exec across a network (to back up clients/hosts), you can feel safe because it uses SSL for all network backup connections. Like Acronis, Symantec offers solutions for Exchange and SQL. Also, the ability to manage Vaults (backup destinations) is superb with Symantec. Just make sure that if a Vault is physically (and permanently) removed, you remove it from within the backup software. Otherwise, it will cause problems.

Figure B

Symantec Backup Exec

Symantec Backup Exec

3: Carbonite

Carbonite (Figure C) is primarily an online backup (although the Business and BusinessPremier plans allow you to back up to an external drive). It’s meant to back up data only. Carbonite is probably one of the most reliable online backup tools and can back up email, documents, POS files, financial data, pictures and other multimedia, and more. But to use Carbonite for Windows Server, you must use the BusinessPremier Plan ($229.00 per year), which will allow you to include as many servers running Window Server 2003/2008/2011 as you like. Unlike Acronis, you won’t be backing up an image of your server with Carbonite — it’s a data-only backup tool. But it’s an excellent addition to any onsite backup solution.

Figure C

Carbonite

Carbonite

4: Windows NT Backup

Windows NT Backup (Figure D) is the free backup solution that comes with any Windows Server. Why do I include it here? Although it just does data backup and doesn’t offer many of the bells and whistles of the other tools, it is one of the only truly reliable backup solutions that will clear the Exchange logs for you. I always set up an NT Backup to run once a week (or month, depending upon the needs), just to have it clear the Exchange logs. Otherwise, you’ll be including a lot of unnecessary data in your backups, causing their size to get out of hand.

Figure D

Windows NT Backup

Windows NT Backup

5: ShadowProtect 4 (Server)

ShadowProtect 4 (Figure E) is probably the least-known product in this list. But it falls into place next to Acronis as a feature-rich tool that can do everything — including recover to dissimilar hardware. ShadowProtect 4 also includes an easy-to-use tool that allows you to consolidate backup image files and convert the backups to either .VHD or .VMDK virtual machines. Another outstanding feature is its granular recovery, which allows for the quick recovery of individual files from within a backup. Unique to ShadowProtect is the Virtual Boot technology, which provides for automatic failover to a virtual server.

Figure E

ShadowProtect

ShadowProtect 4

Which backup?

Every company needs a backup plan. How far you go with your backup depends upon the size of the company, your needs, and your budget. But any of the above solutions will serve as a great place to start — or stop — for your Windows Server backup needs. Do you have a different backup solution to add to the list? Share your recommendations with fellow TechRepublic members.

 
Source: Jack Wallen – TechRepublic
Categories: Logiciel Tags: , ,

10 Amazing and Mysterious Uses of (!) Symbol or Operator in Linux Commands

10/01/2021 Aucun commentaire

Linux-logo-without-version-number-banner-sized-348x196The '!' symbol or operator in Linux can be used as Logical Negation operator as well as to fetch commands from history with tweaks or to run previously run command with modification. All the commands below have been checked explicitly in bash Shell. Though I have not checked but a major of these won’t run in other shell. Here we go into the amazing and mysterious uses of '!' symbol or operator in Linux commands.

1. Run a command from history by command number.

You might not be aware of the fact that you can run a command from your history command (already/earlier executed commands). To get started first find the command number by running ‘history‘ command.

$ history

History shell command

Now run a command from history just by the number at which it appears, in the output of history. Say run a command that appears at number 1551 in the output of ‘history‘ command.

$ !1551

History by number

And, it runs the command (top command in the above case), that was listed at number 1551. This way to retrieving already executed command is very helpful specially in case of those commands which are long. You just need to call it using ![Number at which it appears in the output of history command].

Lire la suite…

Categories: Système Tags: , ,

Track Multiple Files Simultaneously With MultiTail

08/01/2021 Aucun commentaire

https://www.dbsysnet.com/wp-content/uploads/2016/06/multitail-gnome-terminal.pngThe tail utility is one of the most useful tools an admin has — but it’s also a bit limited and dated. For watching two or more logs at once, and much more, you want MultiTail.

The tail utility is one of the most useful admin tools, but it’s limited and outdated. Bring your log-watching capabilities into the 21st century and view multiple logs at one time with MultiTail.

What’s MultiTail? It’s an ncurses utility that can display multiple files using “windows” (much like GNU Screen or Tmux) in a terminal or at the console. It also supports color highlighting, filtering and much more.

To get MultiTail, head over to the download page or see if your operating system already has packages. On Debian-based systems, you should need to look for only the multitail package. The project released an update (5.2.8) on April 14, so the most recent release probably won’t be in your upstream package repo just yet.

Once it’s installed, run multitail and hit F1. It will pop up a help menu with all of its keybindings. You’ll need to scroll down (use the down arrow key) to see all of the commands. It can be deceptive, otherwise, and it looks like you just have a few commands. Let’s look at a couple of the commands you’ll want to start with.

First, run t — this displays the stats for your instance of MultiTail. To add files, use the a command.

If you want to start multitail with a file or output of a command to access, use multitailfilename or multitail filename1 filename2 for more than one file. Use multitail -R 3 -l "command" -R 3 -l "command2" to see two commands displayed in one window.

Using the h command within MultiTail, you can set the height of each window. If you want to search through a window, use / or shift / to highlight the search string. Using I will toggle case sensitivity.

When you’ve used the search feature, you’ll get a buffer that displays in a “window” above the file. You can write this to a file using s, which will bring up a dialog that prompts for a filename to which to save.

If you get a MultiTail session configured just right you can save it for later using w from within the session. It will prompt you for a filename to which to save the script.

Basically, you can do just about anything you’d be able to do with tail and then some. It’s very interactive, and much of its commands have dialogs that will walk you through creating regular expressions or re-arranging windows and more.

The only caveat I have is that, occasionally, MultiTail is a bit crashy. Not wholly unreliable, but I have managed to crash MultiTail a few times while putting it through its paces. (I’ve never managed to crashtail…). But it’s still an invaluable tool to have around for any Linux or UNIX admin.

Joe ‘Zonker’ Brockmeier is a freelance writer and editor with more than 10 years covering IT. Formerly the openSUSE Community Manager for Novell, Brockmeier has written for Linux Magazine, Sys Admin, Linux Pro Magazine, IBM developerWorks, Linux.com, CIO.com, Linux Weekly News, ZDNet, and many other publications. You can reach Zonker at jzb@zonker.net and follow him on Twitter.

Source: ServerWatch

Categories: Système Tags: , ,

How to sniff HTTP traffic from the command line on Linux

05/01/2021 Comments off

sniff HTTP trafficSuppose you want to sniff live HTTP web traffic (i.e., HTTP requests and responses) on the wire for some reason. For example, you may be testing experimental features of a web server. Or you may be debugging a web application or a RESTful service. Or you may be trying to troubleshoot PAC (proxy auto config) or check for any malware files surreptitiously downloaded from a website. Whatever the reason is, there are cases where HTTP traffic sniffing is helpful, for system admins, developers, or even end users.

While packet sniffing tools such as tcpdump are popularly used for live packet dump, you need to set up proper filtering to capture only HTTP traffic, and even then, their raw output typically cannot be interpreted at the HTTP protocol level so easily. Real-time web server log parsers such as ngxtopprovide human-readable real-time web traffic traces, but only applicable with a full access to live web server logs.

What will be nice is to have tcpdump-like sniffing tool, but targeting HTTP traffic only. In fact, httpryis extactly that: HTTP packet sniffing tool. httpry captures live HTTP packets on the wire, and displays their content at the HTTP protocol level in a human-readable format. In this tutorial, let’s see how we can sniff HTTP traffic with httpry.

Install httpry on Linux

On Debian-based systems (Ubuntu or Linux Mint), httpry is not available in base repositories. So build it from the source:

$ sudo apt-get install gcc make git libpcap0.8-dev
$ git clone https://github.com/jbittel/httpry.git
$ cd httpry
$ make
$ sudo make install

On Fedora, CentOS or RHEL, you can install httpry with yum as follows. On CentOS/RHEL, enableEPEL repo before running yum.

$ sudo yum install httpry

If you still want to build httpry from the source on RPM-based systems, you can easily do that by:

$ sudo yum install gcc make git libpcap-devel
$ git clone https://github.com/jbittel/httpry.git
$ cd httpry
$ make
$ sudo make install

Basic Usage of httpry

The basic use case of httpry is as follows.

$ sudo httpry -i <network-interface>

httpry then listens on a specified network interface, and displays captured HTTP requests/responses in real time.

In most cases, however, you will be swamped with the fast scrolling output as packets are coming in and out. So you want to save captured HTTP packets for offline analysis. For that, use either ‘-b’ or ‘-o’ options. The ‘-b’ option allows you to save raw HTTP packets into a binary file as is, which then can be replayed with httpry later. On the other hand, ‘-o’ option saves human-readable output ofhttpry into a text file.

To save raw HTTP packets into a binary file:

$ sudo httpry -i eth0 -b output.dump

To replay saved HTTP packets:

$ httpry -r output.dump

Note that when you read a dump file with ‘-r’ option, you don’t need root privilege.

To save httpry‘s output to a text file:

$ sudo httpry -i eth0 -o output.txt

Advanced Usage of httpry

If you want to monitor only specific HTTP methods (e.g., GET, POST, PUT, HEAD, CONNECT, etc), use ‘-m’ option:

$ sudo httpry -i eth0 -m get,head

If you downloaded httpry‘s source code, you will notice that the source code comes with a collection of Perl scripts which aid in analyzing httpry‘s output. These scripts are found in httpry/scripts/plugins directory. If you want to write a custom parser for httpry‘s output, these scripts can be good examples to start from. Some of their capabilities are:

  • hostnames: Display a list of unique host names with counts.
  • find_proxies: Detect web proxies.
  • search_terms: Find and count search terms entered in search services.
  • content_analysis: Find URIs which contain specific keywords.
  • xml_output: Convert output into XML format.
  • log_summary: Generate a summary of log.
  • db_dump: Dump log file data into a MySQL database.

Before using these scripts, first run httpry with ‘-o’ option for some time. Once you obtained the output file, run the scripts on it at once by using this command:

$ cd httpry/scripts
$ perl parse_log.pl -d ./plugins <httpry-output-file>

You may encounter warnings with several plugins. For example, db_dump plugin may fail if you haven’t set up a MySQL database with DBI interface. If a plugin fails to initialize, it will automatically be disabled. So you can ignore those warnings.

After parse_log.pl is completed, you will see a number of analysis results (*.txt/xml) in httpry/scripts directory. For example, log_summary.txt looks like the following.

To conclude, httpry can be a life saver if you are in a situation where you need to interpret live HTTP packets. That might not be so common for average Linux users, but it never hurts to be prepared. What do you think of this tool?

Source: Xmodulo

Categories: Système Tags: , , ,

Ubuntu Linux Change Hostname (computer name)

17/12/2020 Comments off

I am a new Ubuntu Linux laptop user. I setup my computer name to ‘tom’ during installation but now I would like to change the computer name to ‘jerry’. Can you tell me how do I I remove tom and set it to jerry on Ubuntu Linux? How do I change the Ubuntu computer name from ‘ubuntu’ to ‘AvlinStar’? Can you tell me more about Ubuntu Linux change hostname command?

You can use the hostname command to see or set the system’s host name. The host name or computer name is usually at system startup in /etc/hostname file. Open the terminal application and type the following commands to set or change hostname or computer name on Ubuntu.

Display the current Ubuntu hostname

Simply type the following command:
$ hostname
Sample outputs:

Fig.01: Ubuntu Linux Show the hostname/computer name command
Fig.01: Ubuntu Linux Show the hostname/computer name command

Ubuntu change hostname command

The procedure to change the computer name on Ubuntu Linux:

  1. Type the following command to edit /etc/hostname using nano or vi text editor:
    sudo nano /etc/hostname
    Delete the old name and setup new name.
  2. Next Edit the /etc/hosts file:
    sudo nano /etc/hosts
    Replace any occurrence of the existing computer name with your new one.
  3. Reboot the system to changes take effect:
    sudo reboot

Sample outputs:

Gif 01: Ubuntu Linux Change Hostname Command Demo
Gif 01: Ubuntu change the computer name demo

How to change the Ubuntu server hostname without a system restart?

Type the following commands:
$ sudo hostname new-server-name-here
Next edit the /etc/hostname file and update hostname:
$ sudo nano /etc/hostname
Finally, edit the /etc/hosts file and update the lines that reads your old-host-name:
$ sudo nano /etc/hosts
From:
127.0.1.1 old-host-name
To:
127.0.1.1 new-server-name-here
Save and close the file.

Ubuntu Linux Change Hostname Using hostnamectl

Systemd based Linux distro such as Ubuntu Linux 16.04 LTS and above can simply use the hostnamectl command to change hostname. To see current setting just type the following command:
$ hostnamectl
Sample outputs:

   Static hostname: nixcraft
         Icon name: computer-laptop
           Chassis: laptop
        Machine ID: 291893e6499e4d99891c3cf4b70a138b
           Boot ID: 9fda2365b77841649e40a141fde46537
  Operating System: Ubuntu 17.10
            Kernel: Linux 4.13.0-21-generic
      Architecture: x86-64

To change hostname from nixcraft to viveks-laptop, enter:
$ hostnamectl set-hostname viveks-laptop
$ hostnamectl

Categories: Réseau, Système Tags: , ,