If I have a disk with bad blocks, how to search bad blocks on it under Linux? You can use ‘badblocks’: https://www.systutorials.com/docs/linux/man/8-badblocks/ badblocks [ -svwnf ] [ -b block-size ] [ -c blocks_at_once ] [ -e max_bad_blocks ] [ -d read_delay_factor ] [ -i input_file ] [ -o output_file ] [ -p num_passes ] […
I miss Gnome 2. How to install the MATE fork of Gnome 2 on Fedora 17? MATE is already included into Fedora 17’s repository and is an official feature of Fedora 18. To install MATE on Fedora 17 # yum install @mate-desktop To install softwares usually needed: # yum install mate-media mate-screensaver mate-system-monitor mate-power-manager mate-utils…
How to easily and quickly test the connection between two nodes on Linux? This should be specific to protocol and port. We can use nc (netcat) to test the connection between two servers. For example, to test whether TCP port 1048 can be used on the server (IP 10.0.3.48 as an example) side: On the server: $…
Any tutorials or tips on how to manage LVM? LVM provides a flexible and easy way to management storage disks on Linux. It also provides a set of tools for management. Here are some tutorials and references for managing LVM: LVM man pages: https://www.systutorials.com/docs/linux/man/8-lvm/#lbAL Manage Disk Volume in Linux: http://www.hongkedavid.com/blog/disk_volume.html LVM with Xen: https://www.systutorials.com/b/linux/tag/lvm/ Remove missing phyiscal volumes…
How to find hard links to a file in Linux? To find out all hard links to file1: $ find /home -xdev -samefile file1 Read more: http://linuxcommando.blogspot.com/2008/09/how-to-find-and-delete-all-hard-links.html
In Linux, mmap() is a system call that is used to map a portion of a file or device into the memory of a process. This can be useful for a variety of purposes, such as memory-mapped I/O, shared memory, and virtual memory management. However, when mapping a large range of memory that is larger…
Evolution is a great personal information management tool that provides Email, address book and calendar tools. Evolution provides many enterprise friendly feature such as native support to Microsoft Exchange connectivity for Emails, address books and calendars. Evolution uses various ways including plain files and dconf configuration systems. This post will give an introduction to the…
We ever discussed fixing ports used by NFSv3 so that it can be easily exported to external networks. For NFSv4.1 or higher, things are much easier. The ports for mountd, statd, and lockd are not required in a pure NFSv4 environment. We have less ports to control or allow for connections. Only port 111 and…
This blog will explain about how to add a custom content in a Receipt which will be generated from MPOS in Microsoft Dynamics. Microsoft provides us with certain fields which can be put into the receipt. There are certain fields which a client will ask to show in the receipt. If the desired field is…
What surprises are awaiting the tech world with .NET Core 2.1 Release in 2018? Technology is one of the most dynamic spheres these days. Every single year you will find a new version of an existing software and .NET Core is not an exception. The intentions of these upgradation is to make online activities seamless,…
Quick links to some useful software on Windows including Web browsers, Video/audio player and ssh/scpsftp/vnc tools for connecting to Linux. ssh/scp/sftp/vnc for connecting to Linux For Linux users, it is sometimes unavoidably to use Windows. With Windows, the Linux users will need to connect to Linux for some tasks. Some general software are needed. The…
Technology Hibernate Envers is the frameworks for auditing entities. As the name suggests Hibernate Envers is developed on top of Hibernate, it will on Hibernate and Hibernate implemented JPA. Hibernate Envers provides easy auditing, versioning solution for entity classes. Advantages of Hibernate Envers: Auditing of all mappings defined by JPA specification. Auditing Hibernate specific mappings…
Introduction In this tutorial, we will be learning as how to deploy .NET Core 2.0 MVC web application on Microsoft Public Cloud i.e. Microsoft Azure, using Microsoft Visual Studio 2017 v15.3 For novice Cloud developers, aspiring .NET / Cloud architects, and all other IT professionals associated with the .NET Core framework & Cloud computing, especially…
The encoding of x86 and x86-64 instructions is well documented in Intel or AMD’s manuals. However, they are not quite easy for beginners to start with to learn encoding of the x86-64 instructions. In this post, I will give a list of useful manuals for understanding and studying the x86-64 instruction encoding, a brief introduction…
The metadata checkpointing in HDFS is done by the Secondary NameNode to merge the fsimage and the edits log files periodically and keep edits log size within a limit. For various reasons, the checkpointing by the Secondary NameNode may fail. For one example, HDFS SecondaraNameNode log shows errors in its log as follows. 2017-08-06 10:54:14,488…
Introduction In general, if we want to debug Linux Kernel, there are lots of tools such as Linux Perf, Kprobe, BCC, Ktap, etc, and we can also write kernel modules, proc subsystems or system calls for some specific debugging aims. However, if we have to instrument kernel to achieve our goals, usually we would not…
Introduction As we know, network subsystems are important in computer systems since they are I/O systems and need to be optimized with many algorithms and skills. This article will introduce how QEMU/KVM [2] network part works. In order to put everything simple and easy to understand, we will begin with several examples and then understand…
Abstract Most popular task monitor systems (such as top, iotop, proc, etc) can only get tasks’ disk I/O information like tasks’ I/O utilization percentage every seconds due to kernel timer/tick frequency and high time cost of system interfaces. This article presents I/O Microscopy, a new way to get tasks’ disk I/O information with high accuracy….
With Google algorithm becoming more intelligent with each passing day, the margin for errors has significantly reduced over the past decade. Back in the day, you might get away with keyword stuffing but today, the same offense will strike off your website from Google search engine results. No one wants that, right. To save you…
The word “viral” has received a lot of attention over the last few years and is applied to different types of content to describe how quickly it has spread and gained popularity. Many times, you’ll hear people speak about their idea and how fast it will spread while assuming that it will “go viral”, but…