A log file is a file, often in clear text, which is generated by a software process to record some specific details about the workings of this process.

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76
votes
16answers
58k views

Alternatives to Splunk?

I'm pretty impressed with Splunk, especially version 4. Pretty graphs, alerting (Enterprise only), and fast, accurate, searching. It's a great product. However, the cost just way too high to consider ...
71
votes
1answer
88k views

InnoDB: Error: log file ./ib_logfile0 is of different size

I just added the following lines in /etc/mysql/my.cnf after I converted one database to use InnoDB engine. innodb_buffer_pool_size = 2560M innodb_log_file_size = 256M innodb_log_buffer_size = 8M ...
70
votes
6answers
266k views

How can I read pcap files in a friendly format?

a simple cat on the pcap file looks terrible: $cat tcp_dump.pcap ?ò????YVJ? JJ ?@@.?E<??@@ ?CA??qe?U????иh? .Ceh?YVJ?? JJ ?@@.?E<??@@ CA??qe?U????еz?...
42
votes
14answers
41k views

How to monitor a windows log file in real time? [closed]

There is a already question that asks about opening a large log files. But my intention is different. Is there any application that monitors a log file and updates as it is updated in real time? ...
36
votes
7answers
52k views

Where is my mysql log on OS X?

I checked /var/log and /usr/local/mysql and i can't seem to find the log. I am trying to troubleshoot an error establishing a database connection with a php function.
34
votes
3answers
40k views

My /var/log/btmp file is huge! What should I do?

My /var/log/btmp file is 1.3 GB in size. I've read that the file is "Used to store information about failed login". What does this mean for my server? And can i delete this file?
30
votes
10answers
32k views

Convenient Windows equivalent to tail -f logfile?

Is there some convenient alternative to this on Windows? I always miss this away from Linux. And no I don't consider Cygwin or some other bash port to be "convenient". :) Either a small app that'll ...
27
votes
6answers
3k views

Linux server out of space

I have been asked this question in two consecutive interviews, but after some research and checking with various systems administrators I haven't received a good answer. I am wondering if somebody can ...
25
votes
6answers
12k views

Colorize Monitoring of Logs

I sometimes monitor apache and php error logs using tail under FreeBSD. Is there any way to get colorized output, either using tail or some other command line app? Alternatively, what is your ...
24
votes
2answers
20k views

Understanding a Postfix log file entry

We have a Postfix hub and I'm trying to better understand the information in the mail.log file. I use tools like qshape, pflogsumm.pl and amavis-logwatch to summarize the log files, but I have still ...
20
votes
4answers
46k views

How can I display and log PHP errors on IIS7?

We're running PHP 5.2.5 on an IIS 7 Server and we're having problems making PHP errors visible... At the moment whenever we have a PHP error the server sends back a 500 error with the message "The ...
18
votes
4answers
52k views

How can i fully log all bash scripts actions?

I want to capture ALL the logs data, both with error messages, from my script output, and redirect them all to log file. I have script like below: #!/bin/bash ( echo " `date` : part 1 - start " ssh ...
18
votes
11answers
22k views

Any freeware IIS log analyzer? [closed]

It would be nice to use ASP.NET, but PHP is ok too, and should be hosted in IIS6. EDIT: the logs are from our intranet site.
17
votes
7answers
6k views

Continuously monitor logs with tail that are occasionally rotated

We're using tail to continuously monitor several logs, but when a log is rotated the tail for that file will cease. As far as I understand, the problem is that when the log is rotated, there is a new ...
17
votes
12answers
12k views

Viewing logs on a remote linux server

Are there any nice tools for doing a 'tail -f' on a remote (linux) server? It would be nice to be able to do something like "taillog server_host /var/log/syslog" to view logs on various servers ...
17
votes
7answers
17k views

Can cron write job output to a log *by default* (instead of mail)?

We all know the right way to handle output from cron jobs is to redirect it to a file: 0 * * * * /bin/date >> /var/log/date.log 2>&1 However, sometimes admins are lazy, forgetful, or ...
16
votes
3answers
16k views

what is sensible-mda and do i need it?

I'm running Ubuntu Intrepid, and have been seeing the following my logs: Aug 23 16:01:03 wp1 sm-mta[13700]: n7NFJIad013566: Warning: program /usr/sbin/sensible-mda unsafe: No such file or directory ...
15
votes
4answers
11k views

Shell Scripting: Using find to delete files matching a pattern

I'm trying to write a bash command that will delete all files matching a specific pattern - in this case, it's all of the old vmware log files that have built up. I've tried this command: find . -...
14
votes
1answer
46k views

Managing CBS.log files on Windows 2008R2?

Whilst auditing disk space on our Windows 2008R2 farm we noticed that some servers had quite large C:\Windows\Logs\CBS\CBS.log files (~1.5GB). I was under the impression that this particular log file ...
13
votes
7answers
4k views

How did you implement log management on your servers?

I'm trying to figure out how other people implement their log management systems. I have 20-30 Linux servers and a few Windows boxes (most of them virtualized). We utilize a lot of Perl and Bash ...
13
votes
5answers
40k views

What is a good SQUID Logs Analyzer? [closed]

Can anyone recommend me a good tool for analyzing squid logs ? I'm currently using SARG. Is there something better? I need to easily see what sites were visited/denied, when and by whom. There is ...
12
votes
2answers
29k views

How to forward specific log file outside of /var/log with rsyslog to remote server?

How can I forward message from a specific log file like /www/myapp/log/test.log with rsyslog client to remote rsyslog server? This log file is outside of the directory /var/log.
12
votes
6answers
6k views

Is anybody using Splunk in a large-scale production environment? [closed]

I've been watching the videos at splunk.com and really it's hard to believe that one can get all those features for free, there's still that "where's the catch?" in the back of my head. So it'd be ...
12
votes
7answers
13k views

“Catch-All” access log with Apache Virtual Hosts?

I have many virtual hosts set up on a web server, each one having its own error and access log. The relevant lines of httpd.conf are something like this: ErrorLog /var/log/httpd-error.log LogFormat "...
12
votes
2answers
21k views

Where is ASP.NET Server Log File is Located?

My ASP.NET MVC application on my development box is running wild; I can't even connected to localhost. In order to know what is the problem, I want to find the log file and examine it. Where is the ...
12
votes
2answers
29k views

How to enable error log in lighttpd properly?

I have a Centos 5 system with Lighttpd and fastcgi enabled. It does log access but does not log errors. I have Internal Server Error 500 and no info in log and when I try to open not -existing file ...
12
votes
7answers
14k views

Command line tools to analyze Apache log files [closed]

I have a bunch of Apache log files that I would like to analyze. I'm looking for a tool that doesn't require much setup; something that I can run a log through the command line, without messing around ...
12
votes
5answers
10k views

Proper way to rotate Nginx logs

I would like to achieve rotation of nginx logs that: would work without any extra software (i.e. - best if without "logrotate") would create rotated files with names based on date Best approach is ...
11
votes
3answers
18k views

What is the difference between syslog, rsyslog and syslog-ng?

I am a bit confused in syslog, rsyslog and syslog-ng. From where can I get the source code for syslog()? Is there any difference between rsyslog and rsyslogd?
11
votes
3answers
23k views

How can I move /var/log directory

on our production server, there is a small drive for the main mount point "/" /var/log is taking much space and I have to manually delete some files. How can I move /var/log/ to let's say /home/log ...
11
votes
4answers
847 views

Which logs to track regularly

I run my own server at home for my personal website running Ubuntu Server with Apache, Bind9 and Django. What logs would you suggest are best to keep track of on a regular basis? (rather than on a ...
11
votes
5answers
1k views

Tips on efficiently storing 25TB+ worth million files in filesystem

Say you are confronted with 25 TB worth uncompressed log files and you have at your disposal an array of 20 commodity boxes with collective free storage capacity of 25 TB. How would you store these ?...
11
votes
3answers
3k views

Preferred format of file names which include a timestamp

As we all know "unix" can have anything in a file except '/' and '\0', sysadmins however tend to have a much smaller preference, mainly due to nothing liking spaces as input ... and a bunch of things ...
11
votes
6answers
12k views

Open source tomcat log viewer

I'm managing several tomcat instances (aprox 30-35) and looking for some console to centralize the logs. I tried php-syslog-ng before (no with tomcat), and found it useful. I would like that these ...
10
votes
3answers
7k views

Logrotate: Rotating non-log files?

I have a backup script that compresses various files and directories and creates .tgz archives. Files are named, e.g. ... backup_2010-10-28.tar.gz backup_2010-10-29.tar.gz backup_2010-10-30.tar.gz ...
10
votes
3answers
5k views

How do I shrink the size of a SQL Server log file

I can't figure out how to shrink the size of the databases ldf file. The DBA says I should use backup log dbname with truncate_only And while that looks like it executed correctly in SQL Query ...
10
votes
2answers
4k views

Strange Bittorrent Log On My Server

I don't know if the following log has something to do with my site being down sometime. I have lot of websites on my server and they don't have any logs like the following: 117.169.1.85 - - [03/Jan/...
10
votes
1answer
3k views

iis 7 log file directory

under my log directory I have a list of subdirectories: W3SVC1, W3SVC2, W3SVC3, etc, etc. How do I match those folders with each website on IIS?
10
votes
2answers
10k views

How to set up fail2ban to read multi log in a jail?

How can I configure multiple logpaths for the same rule? I'm trying to write a syntax like this: [apache-w00tw00t] enabled = true filter = apache-w00tw00t action = iptables-allports logpath = /...
10
votes
4answers
9k views

Fast extraction of a time range from syslog logfile?

I've got a logfile in the standard syslog format. It looks like this, except with hundreds of lines per second: Jan 11 07:48:46 blahblahblah... Jan 11 07:49:00 blahblahblah... Jan 11 07:50:13 ...
9
votes
4answers
7k views

Logrotate Successful, original file goes back to original size

Has anyone had any issues with logrotate before that causes a log file to get rotated and then go back to the same size it originally was? Here's my findings: Logrotate Script: /var/log/mylogfile....
9
votes
6answers
6k views

Send email when anyone logs on

My CentOS/RHEL system may have been hacked, I'm not sure. But I'm playing it safe by creating a new slice from scratch. I've installed tripwire, but I'd also like to be emailed when anyone logs in. I ...
9
votes
1answer
8k views

How can I rotate many log files into a different subdirectory per rotation?

I have a directory with many log files, all of which I would like to rotate daily. For organizational purposes I would like to be able to move the rotated logs into a different directory (or ...
9
votes
3answers
13k views

Good Free Tomcat Log Analyser? [closed]

Could someone recommend a good and free program for analysing Apache Tomcat logs. I don't need real-time analysis or anything like that. I have a log and I just want a quick and easy way to get some ...
8
votes
4answers
18k views

Is there a way to remove “Last message repeated x times” from logs?

I have a script that updates me on any changes to the kernel log on my (Debian) servers. The problem is that occasionally the log contains lines like: last message repeated 4 times I realize that ...
8
votes
4answers
6k views

Is this server hacked or just login attempts ? See log

Can someone tell what does this mean? I tried a command like lastb to see last user logins and I see some strange logins from China (server is EU, I am in EU). I was wondering if these could be login ...
8
votes
4answers
14k views

In unix, what's the best way to reduce the size of a massive log file that is actively being written to?

On a linux server, I want to reduce the size of a log file which is several GB big. Cutting off the top half, or maybe the first million lines would work.
7
votes
8answers
16k views

Linux monitor logs and email alerts?

I have a server with a faulty power button that likes to reboot itself. Usually there are warning signs, like the acpid log file in /var/log starts spamming garbage for about 10hrs or so. Is there an ...
7
votes
4answers
248 views

get text between keywords in log file

If I have a log file and want to dump only the text between 1234 and 9876 in to another file, how can i do this easily? If I have a text file like this: idsfsvcvs sdf sdf e e sd vs d s g sg s vc ...
7
votes
1answer
4k views

Different permissions per log file when using rsyslog

Is it feasible to define different permissions per log file, using rsyslog? $FileCreateMode applies to all, but I want different permissions for a specific file.