RSSCategory: TROUBLESHOOTING

How to Use BCC Kernel Tracing Tools for Linux Performance Analysis

Greetings, BCC is now available for Ubuntu and in this article we will be showing you its extended command line use to trace Linux systems for performance monitoring. The BPF Compiler Collection (BCC) is a toolkit for building kernel tracing tools that leverage the functionality provided by the Linux extended Berkeley Packet Filters (BPF). BPF […]

February 15, 2017 | By in TROUBLESHOOTING
| Reply More

5 User Space Debugging Tools in Linux

By definition, debugging tools are those programs which allow us to monitor ,control and correct errors in other programs while they execute. Why should we use debugging tools? To answer this, there are various situations where we get stuck while running some programs and will have the need to understand what exactly happened. For example, […]

December 22, 2014 | By
| Reply More

How to Fix a Broken Initrd Image in Linux

Today, we'll show you how you can fix your broken or accidentally deleted Initrd Image ie. Linux Kernel Image and GRUB Loader in your Ubuntu installed machine.  It should also work for Ubuntu derivatives as well as other distribution. Initrd is a scheme for loading a temporary root file system into memory in the boot process of […]

December 1, 2014 | By
| Reply More

Fix Grub Filesystem Type Unknown Error On Centos / Redhat

LINUX TROUBLESHOOTING GRUB is GRand Unified Bootloader, the default bootloader for Linux kernel based Operating Systems. If you have a dual boot system, like Windows and Linux, then you may have some issues with GRUB. If you install Windows after Linux installation, then Windows puts its own bootloader on the MBR. So GRUB is no […]

October 31, 2012 | By
| Reply More

Fix Error - Locale: Cannot Set LC_ALL to default locale: No such file or directory

Question How to fix the error “locale: Cannot Set LC_ALL to default locale: No such file or directory”. Answer Locales are used in Linux to define which language the user uses. As the locales define the character sets being used as well, setting up the correct locale is especially important if the language contains non-ASCII […]

October 24, 2012 | By
| Reply More

How To Record / Log Failed Login Attempt In Linux

A system administrator needs to monitor any unusual activities on the system. An unauthorized user may try to access the system by trying out different passwords. A feature in Linux that can be used to monitor these failed login attempts is “faillog” utility. The “faillog” command displays all failed login attempts by a user. If there […]

May 10, 2011 | By
| 4 Replies More

Linux Tcp Ports - How To Use Netstat and Iptables For Linux Troubleshooting

It is a well known fact that Linux/Unix systems are mostly used as servers and are often in connection to the internet. In such platforms, access is limited by ports used. The term 'port' means a number access point that is used to access your system much like a telephone number. Ports are usually connected […]

May 8, 2011 | By
| Reply More

How To Fix if Partition Table Entries not in Disk Order

The suggestion given below can help if your partition table is not in a proper disk order. From linux fdisk (fdsik /dev/), choose the advanced menu (by pressing x, afaik), then choose the entry for correcting partition ordering (press 'm' anytime to get some help on commands). You should know that after following the step above, your […]

May 5, 2011 | By
| Reply More

How Linux Who & Last Command Helps for Root Cause Analysis

The last command is very important in linux as it helps in doing root cause analysis of the linux system. Assume that something is changed in the linux system, in this situation you are not sure who has made the changes. Using the 'last' command you can identify who logged in at the particular time when the changes were made. […]

May 2, 2011 | By
| 1 Reply More

3 Commands To Unmount when NFS Mounted Directory is Busy

When you do an NFS mount, it can happen that, for some reasons, we are not able to unmount the disk/partition. When it happens, if we care to lost data, we need to use a safety method to resolve the problem and properly unmount our disk/partition. There are different ways and options we can try […]

February 22, 2011 | By
| Reply More