Apache Web Hosting, Affordable, PHP5, Comcast - Linux Blog

210 Part II . Getting Around in Linux To run the fdisk utility, you must be logged in as root. When displaying partition information, the physical disk information and file system information are also displayed. The commands are issued within the fdiskutility that is run with the device as the argument. None of the changes are saved until the w command is issued. In the example the partitions are displayed and the third partition is deleted. fips The fips utility is not a Linux utility. This utility is not covered on the exam but is useful to know when adding Linux to an existing system. It is a MS-DOS utility provided with Red Hat to resize partitions on hard disks. This utility produces two partitions, the resized original partition and a new partition created from the free space. You then need to delete the newly created partition so the space can be used for Linux. Before using the fips utility it is important to back up data stored on the current partition. The utility is located on the Red Hat CD-ROM in the dosutils directory. The utility is run from the MS-DOS command line, and the arrow keys are used to resize the current partitions. Care should be taken when using this utility. In the The fips utility is similar to PartitionMagic and other commercial software that is Real World used to resize and create new partitions. mkfs Once you have created a partition, the file system must be added so that Linux can use the space. The mkfs utility is used for creating file systems on bare partitions. The mkfs utility is used with several different options, which are shown in Table 5-4. This is actually just a front end for the various utilities covered in Table 5-5. Table 5-4 Options Used with mkfs Option Use -t fstype Specifies the type of file system to be built. If not specified, the default file system type (currently ext2) is used. fs-options File system specific options to be passed to the real file system builder. Although not guaranteed, most file system builders support the following options. -c Check the device for bad blocks before building the file system. -l filename Read the bad blocks list from filename. -v Produce verbose output. -V Produces verbose output, including all file system specific commands that are executed.
You want to have a cheap webhost for your apache application, then check apache web hosting services.

Chapter 5 . Using Partitions and File Systems 209 Option Use q Exits without saving. w Saves changes and exits. m Displays commands. Verifies the partition table. a Toggles the bootable flag. The proper use of the fdiskutility is shown below. In this example the first IDE hard drive is examined, the second partition is deleted and then recreated as an extended partition. Then the utility is exited with the changes saved. # fdisk /dev/hda The number of cylinders for this disk is set to 2495. There is nothing wrong with that, but this is larger than 1024, and could in certain setups cause problems with: 1) software that runs at boot time (e.g., old versions of LILO) 2) booting and partitioning software from other OSs (e.g., DOS FDISK, OS/2 FDISK) Command (m for help):p Disk /dev/hda: 255 heads, 63 sectors, 2495 cylinders Units = cylinders of 16065 * 512 bytes Device Boot Start End Blocks Id System /dev/hda1 * 1 578 4642753+ b Win95 FAT32 /dev/hda2 579 2495 15398302+ f Win95 Ext d (LBA) /dev/hda5 579 580 16033+ 83 Linux /dev/hda6 581 1101 4184901 7 HPFS/NTFS /dev/hda7 1102 1957 6875788+ b Win95 FAT32 /dev/hda8 1958 2467 4096543+ 83 Linux /dev/hda9 2468 2495 224878+ 82 Linux swap Command (m for help): d Partition number (1-10): 2 Command (m for help): n Command action e extended p primary partition (1-4) e Partition number (1-4): 3 First cylinder (1-8190, default 1): 579 Last cylinder or +size or +sizeM or +sizeK (4000-8190, default 8190): 2495Command (m for help): w
If you are searching for cheap webhost for your web application, please visit MySQL5 Web Hosting services.

208 Part II . Getting Around in Linux Swap Linux systems also use up to eight swap partitions. These partitions are used to store temporary data and increase system performance. A swap partition is used as virtual memory and required for a system with less than 16MB of RAM. In the past, the recommended size of the swap partition was equal to the amount of RAM in the system or 16MB, whichever were larger. It is now often recommended that the swap partition be equal to twice the size of the RAM, so a system with 128MB of RAM would need a swap partition of at least 256MB. Kernels earlier than 2.2 were limited to 128MB swap partitions; however, beginning with version 2.2, the swap partition on i386-based systems is 2GB. Linux systems combine the amount of RAM and the swap partition to determine the total amount of virtual memory available to the system. The optimal amount of virtual memory needed by a system varies depending on the applications you re using. In the Real World Remember that RAM is faster than the swap partition contained on the hard disk. If you are working with applications that consume large amounts of memory, you will probably want to invest in adding more RAM to the system. File system tools Several tools are used for creating partitions and file systems on Linux systems. The fdisk utility is used for dealing with partitions on hard disks. The fips utility is used for resizing partitions, and file systems are created using the mkfs utility. You can use these tools together to prepare hard disks for use on a Linux system. Many Linux distributions include tools that automatically create the Linux partitions and file systems during installation. Some people never find it necessary to utilize the fdisk or mkfs utilities. However, the advanced user and systems administrator need to be familiar with the tools. fdisk The fdisk utility is used to manage partitions on Linux systems. This is a command-line tool with the function of the MS-DOS fdisk; however, they are two distinct tools with different options and usage. Table 5-3 covers some of the commands used with the fdisk utility. In the Real World Table 5-3 Commands Used with fdisk Option Use p Displays partition information. d Deletes a partition. n Creates a new partition.
If you are looking for affordable and reliable webhost to host and run your business application visit our ftp web hosting services.

Chapter 5 . Using Partitions and File Systems 207 Creating Partitions and File Systems Objective 2.4 Devices, Linux File Systems, Filesystem Hierarchy Standard Create partitions and filesystems. Create disk partitions using fdisk, create hard drive and other media filesystems using mkfs. When working with disk drives you need to perform several steps before the disk is usable by the system. First, you must partition the disk; this allows the drive to be structured for data storage. Once the disk has been segmented into partitions, you can create the file system. Linux provides the tools necessary to create the partitions and the file systems on a hard disk. This section covers these tools and how to use them. Partition types Hard disk drives used by Linux and other systems follow standard partitioning strategies. The partition information is stored on the physical disk and allows several different operating systems to coexist on a single system. Disk partitioning is useful for a variety of reasons. You can store system data on separate partitions to ensure that all of the various parts of the system have the disk space necessary. Keeping user and system data on separate partitions also allows for a degree of safety by providing a physical separation between space accessed by normal users and that accessed by the system. The reasons for partitioning data are too numerous to list. They can vary from issues related to security, politics, and physical disk issues. Regardless of the reasons for creating partitions, the types of partitions remain the same. Disks can contain primary, extended, and swap partitions. Primary All hard disks containing file systems use a primary partition. This is the first partition created on a disk. If all disk space is used by the primary partition, it will be the only partition located on the disk. It is possible to have multiple primary partitions on one physical disk. These partitions are used for booting and are limited to four on a physical disk. Extended If more than four partitions are needed, you need to create an extended partition. When an extended partition exists on a disk, you can have only three primary partitions. An extended partition by itself is not useful. It acts as a container for logical partitions and can hold many of these logical drives. These partitions are not bootable but enable you to have a large number of partitions on the system. The logical partitions can exist only inside of the extended partition.
We would like to recommend you tested and proved virtual web hosting services, which you will surely find to be of great quality.

206 Part II . Getting Around in Linux Exam Tip Exam questions will reference devices, so understanding this naming scheme is important. Considerations when making a file system Remember several considerations when creating a new file system. The file system does not just contain the data of the files stored on the disk. Some of the disk is used for overhead associated with file systems. This includes space for pointers that store the location of data that comprises files, as well as the file system size and label. All of this information uses space on the disk drive. The default settings for these components can affect what is stored on the partition, so you need to understand these components before creating a new partition. It is more difficult to correct problems once the partition has been created and data is stored in the file system. Inodes The pointers used to identify the location of data stored in files are known as inodes. These are used for UNIX-based file systems and are not used with FAT file systems. When you create a file system, the inodes to be used are also created. This sets the number of files that can be stored on the file system. Unless you specify the number of inodes to be created, Linux will try to determine the number of inodes needed based on the partition size. This can cause wasted space if the file system will contain a small number of large files. Disk space can also be lost if the file system will store a large number of small files. Once the inodes have been filled, no new files can be created. The default inode configuration allows for the partition to be filled with files that are 2K in size. Caution Be sure that you understand the importance of inodes. Once you have run out of inodes on a file system, no new files can be created and the rest of the space on the file system will be unusable. Superblocks The inodes for a file system are stored within the superblock. The superblock is a record that also contains information about file system size and location on the disk. Other important file system configuration information such as cylinders and disk block usage is also stored here. The information stored within the superblock is crucial for accessing the file system. Because of this, several copies of the superblock are stored throughout the disk. This provides fault tolerance so that if one superblock is damaged another can be used and the file system can be restored. A backup of the superblock is always stored every 8K blocks of the file system.
You want to have a cheap webhost for your apache application, then check apache web hosting services.

Chapter 5 . Using Partitions and File Systems 205 Table 5-2 Device Names Device Name Use hd IDE hard drive partitions sd SCSI hard drive partitions sr SCSI CD-ROM drives fd Floppy drives st SCSI tape drives ht IDE tape drives tty Terminals lp Printers pty Remote terminals js Joystick ports midi MIDI ports ttyS Serial ports cua COM ports cdrom CD-ROM drives. This is often just a link to the actual IDE or SCSI device. modem Modem devices The prefixes are combined with a device number. With hard disks partitions the drive is specified with a letter such as a for the first drive, bfor the second drive, and so on. The partition is specified with a number such as 1 for the first partition, 2 for the second partition, and so on. Examples of this naming: hda1 The first partition on the first IDE hard drive. hdb2 The second partition on the second IDE hard drive. cdrom The first CD-ROM drive. cdrom1 The second CD-ROM drive. sda1 The first partition on the first SCSI hard drive. fd0 The first floppy disk drive. These device names are used to address devices on a Linux system. All devices are stored in the /devdirectory. The device names can be linked to other devices; for example, cdrommay be linked to /dev/sr0 if there is a SCSI CD-ROM installed on the system. These links allow for standard addressing of devices on systems. By examining the contents of the /devdirectory you can view the links and exact locations of the devices on a system.
You need excellent and relaible webhost company to host your web applications? Then pay a visit to Inexpensive Web Hosting services.

204 Part II . Getting Around in Linux File system types Many different file systems can be accessed using Linux systems. Table 5-1 shows many of these file systems and their use. Table 5-1 Linux File Systems File System Use iso9660 CD-ROM file system. minux Minux file system. msdos 16-bit MS-DOS FAT file system. vfat 32-bit Windows FAT file system utilizing long filenames. hpfs OS/2 file system. proc Linux processes file system. nfs Network file system used for accessing remote systems. swap Linux swap file system. sysv UNIX System V file system. ext2 Linux file system. These file systems can be thought of as languages. Linux is multilingual but must know the correct language to speak when communicating with each file system. As you can see, Linux supports file systems used by various other operating systems. This is useful for a system that dual boots with these other operating systems. Using the support for these file systems you can access non-Linux partitions for reading and writing files. The NTFS file system used by Windows NT and Windows 2000 is one file system not listed in Table 5-1; however, support for this file system is currently being developed for Linux systems to allow for read and write access to these partitions as well. The Reiser file system, reiserfs, is another not listed in Table 5-1. This is a journaling file system used by some Linux systems to allow for greater recovery in case of a system failure. This file system will be included with later versions of the Linux kernel. Later in this chapter you will learn how to specify the file system using files and commands. Cross-For more information on reiserfs go to http://www.reiserfs.org Reference Along with the option of the file system type, understanding the device names used when working with storage media is important. Table 5-2 shows the various device prefixes used with Linux devices.
You need excellent and relaible webhost company to host your web applications? Then pay a visit to Inexpensive Web Hosting services.

Chapter 5 . Using Partitions and File Systems 203 This chapter covers the tools and practices associated with file systems and their management. Simply put, a file system is a way for the operating system to arrange files on the storage media so it can find them when it needs them. You use these tools to create, maintain, and control the file systems. These tools and concepts are used throughout the book and are important when working with Linux systems. Several exam objectives are covered in this chapter so you need to have a thorough understanding of all material presented here. Linux File Systems Overview As you have already discovered, Linux file systems are discussed throughout the book. File systems are a primary component of all operating systems, and understanding the function and use of these systems is important. You will be required to know the differences in the various file systems as well as the proper use of each. A variety of media can contain files for a Linux system. Hard disks, CD-ROMs, floppies, network drives, and other removable media can all be used to store files. Each of these media uses file systems for organization. These file systems arrange files in a tree-like directory structure with subdirectories branching from the root directory. The media and operating system used to store files dictate the file system used. Linux can support a wide variety of media and file systems depending on the configuration of the Linux kernel. With this support, you can create, access, and modify these file systems. Cross-This chapter covers the usage of file system tools while Chapter 13 details how to Reference install the kernel options. The mount command is used to connect various other file systems to the primary Linux file system, which currently defaults to the ext2 file system. The root user has control over the location of these additional file systems. The root user can grant standard users the proper access to mount specific file systems such as CD-ROMs and floppy disks for use on the system. When working with removable devices, remember that each disk must be mounted to be used. If you wish to access another disk, you must first unmount the current disk, swap the disks in the drive, and then mount the new disk for use. You can also configure file systems to be mounted automatically when the system is started. This ability is useful when working with file systems stored on the network or on local hard disks in the system. The tools and files used to allow these functions are covered later in this chapter.
Please visit Domain Name Hosting services for high quality webhost to host and run your jsp applications.

202 Part II . Getting Around in Linux CHAPTER PRE-TEST 1. Which file contains information on currently mounted file systems? 2. Which command is used to display the number of inodes on a file system? 3. Which command is used to mount all file systems listed in the /etc/fstab file? 4. What is the default file system type for Linux partitions? 5. Which utility is used to create a partition on a Linux system? 6. Which utility is used to format a partition using the Linux swap file system? 7. Which file contains the file systems mounted automatically by the operating system? 8. Which type of partition is bootable? 9. What is the device name used by the second partition on the second IDE drive? 10. Drive information such as labels, blocks, and inode tables is stored where? . Answers to these questions can be found at the end of the chapter. .
Looking for affordable and reliable webhost to host and run your business application? Then look no more and go to servlet web hosting services.

5 CHAPTER Using Partitions and File Systems …. EXAM OBJECTIVES Exam 101 . General Linux, Part 1 2.4 Devices, Linux File Systems, Filesystem Hierarchy Standard Create partitions and filesystems. Create disk partitions using fdisk, create hard drive and other media filesystems using mkfs. Maintain the integrity of filesystems. Verify the integrity of filesystems, monitor free space and inodes, fix simple filesystem problems. Includes commands fsck, du, df. Control filesystem mounting and unmounting. Mount and unmount filesystems manually, configure filesystem mounting on bootup, configure user-mountable removable filesystems. Includes managing file /etc/fstab.
Note: In case you are looking for affordable and reliable webhost to host and run your j2ee application check Vision J2ee Web Hosting services.