centos log for all downloaded files The 15 Best Linux Log Viewer & Log file Management Tools. If you are a Linux lover, you must have some knowledge about Linux log viewer tools. Log viewer gives you a full visual history of everything happening in your Linux system. In the logs file, we will have each piece of information such as application log, system log, event log, script log, rewrite log, process ID, etc. Best Linux Log Viewer Tools. We have compiled a list of 15 log file viewers’ tools to give you clear insight and make sure of what will be best for you. So let’s get started. 1. LOGalyze. LOGalyze does its job quite impeccably with the focus on log management. Also, it has the usability of network observation which comes with the package. When it comes to processing all of your log information in a single place, LOGalyze is helpful. Moreover, you don’t have to worry about whether it’s going to support your requirement or not because it goes with the Linux/Unix servers, network devices, and Windows hosts. This software can detect all of your real-time events with the ability of intensive search. LOGalyze can define your events. Plus, it can alert you by comparing your log info. Moreover, you can close your events in haste with the ticketing system. Features of LOGalyze. LOGalyze is a Syslog UDP/TCP collector that collects plane text files over HTTP/HTTPS, FTP, SFTP. Works as SNMP trap collector. LOGalyze creates real-time multidimensional statistics on individual fields of the log. Offers a web-based customizable user interface based on HTML. Provides various output like- email, HTML online, CSV, XLS. 2. Glogg. If you have long log files that are also quite complicated, then Glogg is the right choice for you to browse and search through it. This multi-platform GUI application is built to make things easier for you. Even if you have very complex log files, this application can do the job at ease. Features of Glogg. This Linux log viewer runs on Unix systems, Windows, and Mac OS. It opens a second window while showing the result of the current search. As read the root file directory from the disk without loading it into memory, it’s much faster. Colorize specific log files and search results. Supports regular expressions like Grep/Egrep. Glogg can also read the UTF-8 and ISO-8859-1 files. 3. GoAccess. When it comes to a weblog analyzer that operates in real-time, GoAccess is the perfect choice for you. This open-source log viewer is quite interactive, which is made for the Unix-type system. For both the *nix system and web browser, this Linux log file viewer can operate in a terminal at ease. Even if you need a visual server report in haste, it comes quite handy with very fast HTTP statistics. Features of GoAccess. Allows custom log format string & Predefined options. This real-time analyzer can be updated on the terminal every 200 ms When it comes to HTML output, it can be updated in one second. Processing logs in the on-disk B+tree database is another ability of this analyzer. A minimal configuration is needed as everything is built-in. It can analyze the hits and visitors count. Bandwidth and metrics determination is also a plus point of this analyzer. It has multiple virtual hosts to monitor which virtual host is consuming most of the server resources. 4. KSystemLog. You can understand your machine’s background work with the KSystemLog. This log viewer read the log file quite differently. If you are a newbie in the game and can’t find your system information or the location of the log files, then this program comes in handy. The earlier statement doesn’t mean that this program is only for a newbie, but advanced users can also use this. Advanced users can observe the issues that are running on their server. Features of Ksystemlog. Supports almost all types of logs (Sys log, Kernel log, Apache log, etc.). Has tab view to display many logs at the same time. Reads one log mode from multiple resources. Displays new log lines in bold. It has a group view to easily display logs considering log level, process, hours, etc. Gives every detail of information for each log file. 5. Graylog. Sometimes Graylog can be used as a SIEM, but basically, this platform is for log management. With this tool, you can collect lots of log data and process it. Plus, storing those files as per your requirement is another great feature of this log management application. Moreover, this log management tool has a perfectly designed interface that allows you to search through your log records. Thus, you can get your desired data quite easily with this Linux log viewer. Features of Graylog. Ksystemlog can ingest any structured data, including log messages and network traffic. Provides a fully customizable dashboard with numbers of a widget. Use standard Boolean search terms for selecting fields and data types. Send real-time alert notifications to admin in various ways like email, text, and Slack. Graylog usually contains sensitive and regulated data so that the system itself remains accessible, secure, and speedy. Has predefined templates to display data. 6. Frontail. Frontail is a node.js made application that streams server logs to the browser. Frontail is a Tail-f with a user interface. It’s an open-source, cross- platform supported tool that runs under Linux, OpenBSD, macOS. Features of Frontail. Frontail scrolls automatically to mark logs. Shows list of unread logs in favicon. Smooth user interface with Default and Dark themes. Highlights important log. Tail multiple files and standard input. Can search the logs and can set filter from the URL parameter. 7. Multitail. Whether it is your log files or command output, you can observe both of them with Multitail. This log viewer allows you to observe them in multiple windows. When it comes to viewing multiple files as an original tale program, Multitail does the job quite impeccably. Multitail can make the functionality of tools like “watch”. Features of Multitail : Shows log more than one file in multiple windows. You can get online help for a particular context. The developer can merge and search multiple log files into one. Log files can be filtered with the assistance of one or a lot of regular expressions. This tool can act like a “visual pipe” for displaying inputs. Configuration can be set from the command line. 8. Logstash. Logstash is a server-side data processing tool to gather, process, and forward events and system log messages. Assemblage is accomplished via configurable input plugins with raw socket/packet communication, file tailing, and several system messages. This Linux log file Viewer can load unstructured data quickly, offers you lots of pre-built filters so you can transform and index data, and has a flexible plugin architecture. Features of Logstash: Logstash can insert data from various sources and can send it to multiple destinations. Can insert any shapes, sizes, and sources of data. Has unified integration with Elasticsearch, Beats, and Kibana. When it comes to processing the HTTP request and sending a response, this tool is pretty handy. Logstash is also used for sensor data and the Internet of things. Like Apache and windows events logs, this tool can process all types of data. 9. Logwatch. Logwatch is a powerful multipurpose log analyzer that is considered an integrated report of all the actions on a server. It can recap logs from different machines in a single report. This Linux log viewer generates a periodic report specified by user criteria. The incredible thing about this tool is it scans log files and presents data in a human-readable form. Features of Logwatch: Logwatch sent instant log alert when any security Breach or performance issue happened. The developer can use a personalized dashboard focusing on their importance. Powerful search option, including a smart filtering system. Has pre-made reports that help developers to create standard reports easily. The most important feature of Logwatch is, it detects intruders and security breaches. Using this tool, developers can protect the network from an internal security breach and analyze security threats. 10. Logcheck. This Linux log file viewer is an easy and widely used tool that allows a system administrator to analyze the log files created upon hosts under their control. After filtering out the normal entries, it does mail a summarized report to the developer. Logcheck helps to spot the problem on the server and security breach. If any issue happened, it sends mail to the administrator periodically. Features of Logcheck. Logcheck has a Cloud-based dispatch management system. The developer can access this tool using their mobile phone also. Gives instant information about security problems. The log can be filtered easily with regular expression. Sends instant notification by email. Has Important pre- made report templates to make an instant report. 11. Xlogmaster. When it comes to having a contented and quick way to observe every log file on your system, the Xlogmaster can withstand the competition. This GUI program has the most convenient way to observe everything that’s happening in your system. This program is based on the graphical interface, and because of its easy configuration, any user can manipulate this interface as per their requirement. Features of Xlogmaster. Xlogmaster has an easy plugin integration system. Has a completely customizable menu. Log execution allows pipes. Has excellent Keyboard accelerators. Support for a system-wide entry database & personal entry database. Xlogmaster now catches log file rotations. 12. Lnav. This Linux log viewer is based on an advanced console system with having lots of similarities with others. However, this particular log viewer is quite popular with developers because of its advanced features. Also, it can decompress all the zip-type files. When you are using this particular log viewer, you won’t need multiple windows. Because of its merging capabilities, you can observe more than one file in a single window. Plus, all the warnings and errors in this log viewing process will be highlighted automatically. Features of Lnav. All log files are merged into a single message on timestamps. Users can easily monitor all the logs from one window. Lnav can extract data automatically. Automatic log format detection is the most amazing feature of Lnav. It Displays only those lines that match or not with a set of regular expressions. The Timeline view gives a histogram of the message over time. Can perform SQL queries without loading the data into the SQL database. 13. Nagios. The Nagios is also another open-source log monitoring tool. It checks from time to time on vital parameters of all the applications that are running by the system. Alongside the log files, you can monitor the usage of the memory and space in your disk. Also, viewing the microprocessor loads and currently running processes is a plus for this log monitoring tool. Features of Nagios. Nagios can monitor almost all types of the network like SMTP, POP3, HTTP, NNTP, PING, etc. It has an optional web interface to view real- time network status, notifications, problem history, log files, etc. Capability to describe event handlers to be route during service or host events for hands-on problem resolution. Has easy parallelized service checking. Simple plugin design and UI allow users to customize their service check. Nagios can monitor host resources as memory usage, disk space, microprocessor load, etc. 14. Journalctl. This small system administrator tool named Journalctl comes in pretty handy. Plus, this tool has comfortable operations for Linux-based users. Basically, Journalctl is a journal’s message displaying tool which can be used for querying also. Usually, the journal has lots of binary files, and that’s why journalctl is a perfect method to view all the messages from it. Features of Journalctl. You can view logs in Syslog format with Journalctl, which is quite traditional. When it comes to filtering the entries, the file path can be specified as an argument. The output is paged through less by default, and long lines are “truncated” to the screen. Additional constraints can be added using some specified options. 15. Swatch. Swatch is a simple log watcher that was designed to monitor system activity. Swatch can watch any type of logs for regular expression as per your configuration. Also, you can use the command line to run these tools in the background. This open-source log viewer tool is now called Swatchdog. Features of Swatch. It sweeps your log file on a regular basis to look for the user-defined keyword. This tool has protection from DOS attacks. It can be defined to watch for specific logs. With this log viewer, you can watch out for any suspicious activities. Ending Thoughts. In this article, we have tried to sort out some of the best Linux log viewer and log file management tools that ultimately help you choose the best one for your system. I strongly suggest you install a few of them and justify the requirement for getting the best one. Is this article helpful? If so, please take a moment to share it on your social media. And don’t forget to share your experiences and suggestion in the comment below. How do I download a file from the internet to my linux server with Bash [closed] Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 8 years ago . I recently had to upgrade to a VPS server (HostGator Linux) because I wanted to run a script that was a bit more complicated than the regular PHP db manipulation. I'm trying to install a JDK and Apache Ant (if it matters, for compiling Android Apps on server). I watched tutorials on Linux Bash and started using it. I am currently trying to install Java (with JDK and JRE) on to the server. CentOS / RedHat : Beginners guide to log file administration. The system log daemon is responsible for logging the system messages generated by applications or kernel. The system log daemon also supports the remote logging. The messages are differentiated by facility and priority. In principle, the logs handled by syslog are available in the /var/log/ directory on Linux system : where some of the logs are dumped under a subdirectory like cups, samba, httpd. Among the logs under /var/log the /var/log/messages is the most common one as the kernel / core system logs are held there. The kernel modules generally dumps there too. So, for problem diagnosis / monitoring the /var/log/messages is the primary log file to examine. The system log daemon/service and it’s configuration file differs depending on the version of Linux used i.e.: Rsyslog. Rsyslog is the new logging daemon starting RHEL6 to compete with the old syslog-ng daemon. Few of the benefits rsyslog daemon provides over syslog-ng are : 1. Reliable Networking – Rsyslog uses TCP instead of UDP which is more reliable. TCP uses the acknowledgment and retransmission capabilities. – with Rsyslog daemon you can specify multiple destination hosts/files for messages delivery if rsyslogd is unable to deliver a message to aprticular destination. 2. Precision – it is possible to filter messages on any part of log message rather than the priority of the message and the original facility. – support for precise timestamps to log messages that the syslog daemon. 3. Other features – TLS encryption – ability to log to SQL databases. rsyslog.conf. The configuration file – /etc/rsyslog.conf for the rsyslogd daemon is used to handle all the messages. The configuration file basically provides rules statements which in turn provides 2 things : Selectors and actions. Selectors are made up of 2 things facilities and priorities. They specify which messages to match. The action field specifies what action to apply to the matched message. For Example : – The messages with with a facility of kernel and priority debug are logged into the file /var/log/kernlog. – Priority statements are hierarchical in selectors. Rsyslog matches all the messages with specified priority and higher. So all the messages from kernel with priority debug and higher are logged. Debug being the lowest priority all the messages with facility kern are matched. – Another way to do this is to use the asterisk (*). For example : – multiple selectors can be specified on a single line separated by semicolons. This is useful when same action needs to be applied to multiple messages. – when a file is listed in action field, the matched messages are written into the file. – There can be other devices such as FIFO, terminal etc to write the messages to. – If a username is listed in action field, the matched messages are printed to the users all the terminals if they are logged in. – (*) in the action field specifies. Facilities. The facility is used to specify which type of program or application is generating the message. Thus enabling the syslog daemon to handle different sources differently. The table below lists the standard facilities and their description : Facility Description auth/authpriv security/authorization messages (private) cron clock daemon (crond and atd messages) daemon messages from system daemons without separate facility kern kernel messages local0 – local7 reserved for local use lpr line printer subsystem mail messages from mail daemons news USENET news subsystem syslog messages generated internally by system log daemon user generic user-level messages uucp UUCP subsystem. Priority. The priority of a message signifies the importance of that message. Table below lists the standard priorities and their meanings : Priority Description emerg system is unusable alert action must be taken immediately crit critical conditions err error conditions warning warning conditions notice normal but significant importance info informational messages debug debugging messages. Log Rotation. Log files grow regularly overtime and thus they needs to be trimmed regularly. Linux provides a utility to provide this functionality without user intervention. The logrotate program can be used to automate the log file rotation. The basic logrotate configuration is done in the configuration file /etc/logrotate.conf . In the configuration file we can set options such as – how frequently logs should be rotated and how many old logs to be kept. As per the above logrotate configuration file the logs are rotated every week (renaming the existing log to filename.number order): minsize 1M – logrotate runs and trims the messages files if the file size is equal to or greater than 1 MB. rotate 4 – keep the most recent 4 files while rotating. create – create new file while rotating with specified permission and ownership. include – include the files mentioned here for the daemon specific log rotation settings. – The logrotate daemon mainly reads all the configuration from file /etc/logrotate.conf and then includes daemon specific configuration files from /etc/logrotate.d/ directory. – The logrotate daemon along with rotation and removal of old logs, allows compression of log files. – The daemon runs daily from /etc/cron.daily/logrotate. Logwatch. – RHEL systems are also shipped with logwatch packages. – Logwatch is used to analyze the logs to identify any interesting messages. – Logwatch can configured to analyze logfiles from popular services and email administrator the results. – It can be configured on hourly or nightly basis for any suspicious activity. By default in a RHEL system, it is run on nightly basis and report is mailed to root user. 12 Critical Linux Log Files You Must be Monitoring. Log files are the records that Linux stores for administrators to keep track and monitor important events about the server, kernel, services, and applications running on it. In this post, we’ll go over the top Linux log files server administrators should monitor. Share on Facebook Share on Twitter Share on Linkedin Send email. What are Linux log files. Log files are a set of records that Linux maintains for the administrators to keep track of important events. They contain messages about the server, including the kernel, services and applications running on it. Linux provides a centralized repository of log files that can be located under the /var/log directory. The log files generated in a Linux environment can typically be classified into four different categories: Application Logs Event Logs Service Logs System Logs. Why monitor Linux log files. Log management is an integral part of any server administrator’s responsibility. By monitoring Linux log files, you can gain detailed insight on server performance, security, error messages and underlying issues by. If you want to take a proactive vs. a reactive approach to server management, regular log file analysis is 100% required. In short, log files allow you to anticipate upcoming issues before they actually occur. Which Linux log files to monitor. Monitoring and analyzing all of them can be a challenging task. The sheer volume of logs can sometimes make it frustrating just to drill down and find the right file that contains the desired information. To make it a little easier for you, we will introduce you to some of the most critical Linux log files that you must be monitoring. /var/log/ messages. What’s logged here?: This log file contains generic system activity logs. It is mainly used to store informational and non-critical system messages. In Debian-based systems, /var/log/syslog directory serves the same purpose. How can I use these logs?: Here you can track non-kernel boot errors, application-related service errors and the messages that are logged during system startup. This is the first log file that the Linux administrators should check if something goes wrong. For example, you are facing some issues with the sound card. To check if something went wrong during the system startup process, you can have a look at the messages stored in this log file. /var/log/auth.log. What’s logged here? All authentication related events in Debian and Ubuntu server are logged here. If you’re looking for anything involving the user authorization mechanism, you can find it in this log file. How can I use these logs?: Suspect that there might have been a security breach in your server? Notice a suspicious javascript file where it shouldn’t be? If so, then find this log file asap! Investigate failed login attempts Investigate brute-force attacks and other vulnerabilities related to user authorization mechanism. /var/log/secure. What’s logged here? RedHat and CentOS based systems use this log file instead of /var/log/auth.log. It is mainly used to track the usage of authorization systems. It stores all security related messages including authentication failures. It also tracks sudo logins, SSH logins and other errors logged by system security services daemon. How can I use these logs?: All user authentication events are logged here. This log file can provide detailed insight about unauthorized or failed login attempts Can be very useful to detect possible hacking attempts. It also stores information about successful logins and tracks the activities of valid users. /var/log/boot.log. What’s logged here? The system initialization script, /etc/init.d/bootmisc.sh, sends all bootup messages to this log file This is the repository of booting related information and messages logged during system startup process. How can I use these logs?: You should analyze this log file to investigate issues related to improper shutdown, unplanned reboots or booting failures. Can also be useful to determine the duration of system downtime caused by an unexpected shutdown. /var/log/ dmesg. What’s logged here? This log file contains Kernel ring buffer messages. Information related to hardware devices and their drivers are logged here. As the kernel detects physical hardware devices associated with the server during the booting process, it captures the device status, hardware errors and other generic messages. How can I use these logs?: This log file is useful for dedicated server customers mostly. If a certain hardware is functioning improperly or not getting detected, then you can rely on this log file to troubleshoot the issue. Or, you can purchase a managed server from us and we’ll monitor it for you. /var/log/kern.log. What’s logged here? This is a very important log file as it contains information logged by the kernel. How can I use these logs?: Perfect for troubleshooting kernel related errors and warnings. Kernel logs can be helpful to troubleshoot a custom-built kernel. Can also come handy in debugging hardware and connectivity issues. /var/log/ faillog. What’s logged here? This file contains information on failed login attempts. How can I use these logs?: It can be a useful log file to find out any attempted security breaches involving username/password hacking and brute-force attacks. /var/log/ cron. What’s logged here? This log file records information on cron jobs. How can I use these logs. Whenever a cron job runs, this log file records all relevant information including successful execution and error messages in case of failures. If you’re having problems with your scheduled cron, you need to check out this log file. /var/log/yum.log. What’s logged here? It contains the information that is logged when a new package is installed using the yum command. How can I use these logs?: Track the installation of system components and software packages. Check the messages logged here to see whether a package was correctly installed or not. Helps you troubleshoot issues related to software installations. Suppose your server is behaving unusually and you suspect a recently installed software package to be the root cause for this issue. In such cases, you can check this log file to find out the packages that were installed recently and identify the malfunctioning program. /var/log/ maillog or /var/log/mail.log. What’s logged here? All mail server related logs are stored here. How can I use these logs? Find information about postfix, smtpd, MailScanner, SpamAssassain or any other email related services running on the mail server. Track all the emails that were sent or received during a particular period Investigate failed mail delivery issues. Get information about possible spamming attempts blocked by the mail server. Trace the origin of an incoming email by scrutinizing this log file. var/log/httpd/ What’s logged here? This directory contains the logs recorded by the Apache server. Apache server logging information are stored in two different log files – error_log and access_log. How can I use these logs?: The error_log contains messages related to httpd errors such as memory issues and other system related errors. This is the place where Apache server writes events and error records encountered while processing httpd requests. If something goes wrong with the Apache webserver, check this log for diagnostic information. Besides the error-log file, Apache also maintains a separate list of access_log. All access requests received over HTTP are stored in the access_log file. Helps you keep track of every page served and every file loaded by Apache. Logs the IP address and user ID of all clients that make connection requests to the server. Stores information about the status of the access requests, – whether a response was sent successfully or the request resulted in a failure. /var/log/mysqld.log or /var/log/mysql.log. What’s logged here? As the name suggests, this is the MySQL log file. All debug, failure and success messages related to the [mysqld] and [mysqld_safe] daemon are logged to this file. RedHat, CentOS and Fedora stores MySQL logs under /var/log/mysqld.log, while Debian and Ubuntu maintains the log in /var/log/mysql.log directory. How can I use this log? Use this log to identify problems while starting, running, or stopping mysqld. Get information about client connections to the MySQL data directory You can also setup ‘long_query_time’ parameter to log information about query locks and slow running queries. Final Takeaway. While monitoring and analyzing all the log files generated by the system can be a difficult task, you can make use of a centralized log monitoring tool to simplify the process. Some of our customers take advantage of using Nagios Log Server to manage their server logs. There are many opensource options available if that’s out of the budget. Needless to say though, monitoring Linux logs manually is hard. So if you want to take a truly proactive approach to server management, investing in a centralized log collection and analysis platform which allows you to view log data in real-time and set up alerts to notify you when potential threats arise. How to download a file from ubuntu virtual machine using Azure powershell script. I have created an Ubuntu VM on Azure and I want to download a file stored in one of the directories of this VM. I want to do this using Powershell. 2 Answers 2. If you just want to grab a couple files, then you can use pscp. You can download pscp from here: http://www.chiark.greenend.org.uk/ If you want to do this more than once from multiple clients you can just serve the files with a web server, e.g. Apache. Then you can just use Invoke-WebRequest to download the files via HTTP. Virtual machines in azure are completely locked down. Do you just need to download the file once? I am trying to understand your requirement of using PowerShell. Here are a few options: 1. manually ftp the file from ubuntu to a FTP server and download it from there. 2. second option for you is to use Azure command line tools that run on ubuntu. you should install Azure CLI https://github.com/Azure/azure-xplat-cli. There are instructions for Ubuntu distributions. One Azure CLI has been isntalled you can use the azure storage command line options to tranfer the file to an azure storage container. After the files in an azure container you can use PowerShell to download it. You can also use Azcopy tool to down the file from the container.