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Showing posts from October, 2009

Installing ns-3.37 and ns-3.35 in Ubuntu | Ubuntu 22.04 | NS3

Multiple Versions of ns3 in Ubuntu 22.04 In this post, we are going to install two versions of ns3 namely ns-3.35 and ns-3.37  My OS is : Ubuntu 22.04 LTS (Long Term Support) ns-3.35 uses waf and (./waf --run scratch/first)  ns-3.37 uses cmake  (./ns3 run scratch/ So we will install both the packages  Go through the video for complete instructions To start with  $ sudo apt update  $ sudo apt install build-essential autoconf automake libxmu-dev g++ python3 python3-dev pkg-config sqlite3 cmake python3-setuptools git qtbase5-dev qtchooser qt5-qmake qtbase5-dev-tools gir1.2-goocanvas-2.0 python3-gi python3-gi-cairo python3-pygraphviz gir1.2-gtk-3.0 ipython3 openmpi-bin openmpi-common openmpi-doc libopenmpi-dev autoconf cvs bzr unrar gsl-bin libgsl-dev libgslcblas0 wireshark tcpdump sqlite sqlite3 libsqlite3-dev  libxml2 libxml2-dev libc6-dev libc6-dev-i386 libclang-dev llvm-dev automake python3-pip libxml2 libxml2-dev libboost-all-dev  I have downloaded both the versions of ns3 fr

Introduction to Proc File System

The proc file system provides information on the current status of the Linux kernel and running process. It also allows modifications of kernel parameters in simple ways during runtime Each process in the system that is currently running is assigned a directory /proc/pid, where pid is the process identification number of the relevant process There are also files and directories for process independent information such as loaded modules, used bus systems etc. Disadvantages of Proc There is no interface for the individual files, every user has to find out where and how the information that is required is hidden in the file Another disadvantage is that all information is output as strings, therefore conversion is always necessary for further processing Structure of File system struct proc_dir_entry { unsigned short low_ino; //inode number unsigned short namelen; //length of the name const char *name; //name of the entry mode_t mod

The Ext2 File System

The initially developed file system was Minix which uses a partition of 64MB and the filenames of no more than 14 characters. After that, A file system called ext was developed which uses a partition size of 2GB and filenames of 255 characters but it was slow compared with Minix. Later the file system for Xia was developed with a partition size of 2GB and 248 characters in filename comparatively faster that Ext file system Finally, Ext2 file system was developed with a faster operation. Structure of ext2 File system The ext2 file system was influenced by the BSD Fast File System (BSD FFS). Thus a partition is divided into a number of block groups, corresponding to the cylinder groups in FFS, with each block group holding a copy of the superblock and inode blocks and data blocks. The objective for developing the block groups is that The data block should be close to the inodes File inodes close to their directory inodes