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Don’t want to mess with iptables? (1, 2, 3) Well in Ubuntu there’s an easier way with the Uncomplicated Firewall. Originally posted at Ubuntu Unleashed and further covered at the Ubuntu Wiki.
Here is an overview on howto use ufw the Uncomplicated Firewall. Enjoy.
This is a comprehensive HOWTO to change your TTY (Ctrol+Alt+F1) and bootscreen resolution. I am sure we have all noticed the low resolution used while Linux is booting up, and also of the TTY (Ctrol+Alt+F1). The resolution of the TTY is set as a paramater given to the kernel before it loads. GRUB is responsible for booting the kernel, so we need to tell GRUB to tell the kernel what resolution we want. GRUB’s list of boot options is contained in the file /boot/grub/menu.lst.
The system utility fsck (for “file system check” or “file system consistency check”) is a tool for checking the consistency of a file system in the Unix system and clones thereof.
Generally, fsck is run automatically at boot time when the system detects that a file system is in an inconsistent state, indicating a non-graceful shutdown, such as a crash or power loss. Typically, fsck utilities provide options for either interactively repairing damaged file systems (the user must decide how to fix specific problems), automatically deciding how to fix specific problems (so the user doesn’t have to answer any questions), or reviewing the problems that need to be resolved on a file system without actually fixing them.
Fsck can also be run manually by the root account if there is believed to be a problem with the file system. However, running fsck on a mounted file system can potentially cause severe data corruption/loss.
Prerequisite: Basics of partitioning with fdisk and formatting with mkfs
So you learned a bit about fdisk and are familiar with mkfs a bit so far. But what about giving up some of your hard-drive for swap space? First let’s start off with what is swap space.
Physical memory is a limited resource on a computer. Only so many processes can fit in physical memory at any one time, though many more may actually be ready to run or execute. Swapping and paging algorithms allow processes or portions of processes to move between physical memory and a hard-drive (or in rare moments, usb drives). This frees up space in physical memory.
Swap space (called a paging file in Windows) is an area on disk that temporarily holds a process memory image. When physical memory demand is sufficiently low, process memory images are brought back into physical memory from the swap area on disk. Having sufficient swap space enables the system to keep some physical memory free at all times.
This type of memory management is often referred to as virtual memory and allows the total number of processes to exceed physical memory. Virtual memory enables the execution of a process within physical memory only as needed. However, swapping does have a downside. Compared to memory, disks are very slow. Memory speeds can be measured in nanoseconds, while disks are measured in milliseconds, so accessing the disk can be tens of thousands times slower than accessing physical memory. The more swapping that occurs, the slower your system will be. Sometimes excessive swapping or thrashing occurs where a page is swapped out and then very soon swapped in and then swapped out again and so on. In such situations the system is struggling to find free memory and keep applications running at the same time. In this case only adding more RAM will help.
Gone are the days are absolutely having to know fdisk and mkfs to get started with Linux as a desktop. Most installers now set up everything for you on the install, in fact, most also setup logical volume management as well. But fdisk and mkfs are still very useful tools when you need to manually partition and format a disk. Throughout this tutorial I’ll walk you through creating and deleting partitions and the basic functions of fdisk and mkfs in linux. A follow-up tutorial will be written specifically for swap partitions and will touch back on this fdisk tutorial as well.
The X.Org Server (home page) is the official reference implementation of the X Window System. The current stable release is 1.4.0, released as part of X11R7.3 on 6 September 2007. It is both open source and free software. The project is supported and overseen by the X.Org Foundation and is hosted by freedesktop.org.
There’s a file in your linux system within /etc/X11/ called xorg.conf. X.org (also called the X11) server is mostly controlled through a configuration file, xorg.conf, for its initial setup. This controls much of the video output for your linux machine but also controls various peripherals as well. We’re not going to cover the entire file as there is far to much to cover but we will introduce the structure of the file and common areas new users to linux might have to face.
I found much advice on mounting NTFS partitions, anecdotal, fragmented, mostly good advice in the major Suse community support forums. But I was confused by the diversity. And some advice was problematic. Here is a consolidation.
It can be a good idea to periodically check for bad blocks. This is done with the badblocks command. It outputs a list of the numbers of all bad blocks it can find. This list can be fed to fsck to be recorded in the filesystem data structures so that the operating system won’t try to use the bad blocks for storing data. The following example will show how this could be done.
