Networking

Front 1

File corruption can occur as the result many things.

Back 1

Improper system shutdown, magnetic fields from motors and other electrical devices near the data, or an area of the disk going bad can cause file corruption.

Front 2

The three most common types of backups are

Back 2

full, incremental, and differential backups

Front 3

Backup methods performed by organizations vary. However, all organizations take a number of factors into account when determining which method to utilize:

Back 3

The criticality of the dataThe amount of data to be backed upThe time window available to do backupsFunds available for a backup system

Front 4

The differential backup is a compromise between

Back 4

a full backup and an incremental backup

Front 5

To adequately test the capability to recover from data lost, the network support staff should be able to accomplish the following restoration tasks, which are

Back 5

Restore a file, Restore a directory, Restore a file system, Restore a harddrive

Front 6

Restore a file

Back 6

Thousands of files typically are backed up in any organization. If a user accidentally deletes or overwrites a file, an administrator should be able to find that file on the backup tapes and restore it to the user's home directory on a server or on the workstation.

Front 7

Restore a directory

Back 7

If a directory is damaged, an administrator should be able to restore the entire directory structure, with all subdirectories and files intact.

Front 8

Restore a file system

Back 8

If necessary, an administrator should be able to restore an entire file system.

Front 9

Restore a hard drive

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In the event of a total failure of a hard drive, an administrator should be able to recreate the contents of the original drive, including the operating system, applications software, and data, if applicable.

Front 10

Streaming magnetic tape is the most common media for backing up large amounts of data because it is

Back 10

inexpensive and can store large amounts of data.

Front 11

Tape drives are

Back 11

sequential recording devices

Front 12

If volume management is not running on a system, the vold daemon is

Back 12

not running

Front 13

By default, volume management is

Back 13

is always running on the system to automatically manage CD ROMs, floppy diskettes, and removable SCSI disks, such as Zip and Jaz disks.

Front 14

When the user inserts a CD ROM into the drive it is automatically detected. However, volume manager does not automatically detect when the user inserts a

Back 14

floppy into the floppy drive

Front 15

The volcheck (volume check) command or Open Floppy option on the CDE File Manger File menu, instructs Solaris to do the following:

Back 15

1) Check the floppy drive 2) Determine the disk type, whether UNIX or DOS 3)Temporarily place or mount the floppy disk under the /floppy directory of the hard drive.

Front 16

To access a formatted disk from the command line:

Back 16

1) Change directories to /floppy 2)Type ls and press Enter. The name of the diskette is displayed as the name of a directory. 3)Type cd diskette-name and press Enter. 4)Type ls and press Enter. The files on the diskette are displayed. The student can copy to and from the diskette using the cp command.

Front 17

To eject a floppy diskette the student must not be in the /floppy directory. The "Device busy" message will appear if the student is in the /floppy directory. Once out of the /floppy directory, the student then types

Back 17

eject fd

Front 18

Later in this chapter the student will be introduced to two popular UNIX backup commands

Back 18

tar and cpio

Front 19

In order to copy files to a diskette using either tar or cpio the diskette must be formatted, using

Back 19

fdformat or the CDE format command

Front 20

Manager window displays the contents of the CD ROM. The student can access data from this window and the command line interchangeably using the

Back 20

pathname /cdrom/cdrom0

Front 21

To eject the CD ROM the student must not be in the

Back 21

cdrom directory

Front 22

Before using a new floppy disk, the disk must first be

Back 22

formatted

Front 23

Mtools is a

Back 23

collection of utilities to access MS DOS disks from UNIX without mounting the disks

Front 24

Most floppy disks are sold with the low level format already done. The student will need to do it only in exceptional cases. Such cases would be when the user thinks a disk has

Back 24

corruption or one or more bad blocks.

Front 25

Thefdformat command is used to

Back 25

do a low level format on a new floppy disk

Front 26

Device names tend to vary between versions of UNIX. The standard floppy disk drive in a Linux system is accessed using the

Back 26

device path /dev/fd0

Front 27

To perform a low level format of a floppy disk, use the command:

Back 27

fdformat /dev/fd0

Front 28

The command to create a file system on a standard floppy is

Back 28

mkfs -t ext2 /dev/fd0 1440

Front 29

The -t ext2 tells mkfs what

Back 29

file system type to make

Front 30

A standard 1.44MB floppy has 80 tracks with

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18 sectors each

Front 31

If a student is using a graphical display such as GNOME, a gfloppy may be

Back 31

used to accomplish floppy formatting of either type, including putting a file system on it

Front 32

In GNOME, gfloppy may be found on the Utilities menu. It may also be run as a

Back 32

shell command

Front 33

Use the mount command to

Back 33

mount a floppy disk with a UNIX file system on it

Front 34

If a correct set of options has been defined in the file /etc/fstab to allow this operation, the command to mount a floppy disk is:

Back 34

mount /mnt/floppy

Front 35

When the student is finished with a UNIX mounted floppy, it must be

Back 35

unmounted

Front 36

the umount command for floppys

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umount /mnt/floppy

Front 37

In GNOME, user mountable drives may be mounted and unmounted using

Back 37

the Drive Mount applet

Front 38

the student may also install a Drive Mount applet in a panel and configure its properties to work with

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the CD ROM drive

Front 39

The student may mount and unmount CDs as nonroot from a terminal window using these commands:

Back 39

mount /mnt/cdrom, umount /mnt/cdrom

Front 40

The UNIX operating system has several integrated utilities that allow

Back 40

multiple files to be backed up and compressed

Front 41

The tar (tape archive) command enables

Back 41

the student to back up single or multiple files in a directory hierarchy

Front 42

The tar command is standard with all

Back 42

versions of the UNIX operating system

Front 43

tar originally was developed for use with

Back 43

tape drives

Front 44

The tar command can create an archive from a

Back 44

single file

Front 45

Tarballs

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which are groups of files combined into one

Front 46

The most frequently used options available with the tar command are

Back 46

c, t, and x

Front 47

tar functions are

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one letter characters used to create a tar file, view the contents of a tar file, or extract files from a tar file

Front 48

tar Functions: c (create)

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is used to archive one or more files or directories to create an archive file.

Front 49

tar Function: t (table of contents)

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is used to see a table of contents of the tar file. This is a listing of the files that were combined to make the one tar file.

Front 50

tar Function: x (extract)

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is used to extract the file or files from the archive and separate them into multiple files again. The tar file still exists after this is done.

Front 51

Compression is a valuable tool because

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it reduces the amount of disk space that files occupy, while still keeping the files readily available.

Front 52

The compress utility uses a special format to reduce the size of the file anywhere from

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20 percent to 80 percent, depending on the type of file

Front 53

If the compress utility determines that the file cannot be compressed or that there will be no reduction in file size, the file will

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remain unchanged.

Front 54

When files are compressed with the compress command, the existing file is

Back 54

replaced using the same name but with a .Z suffix appended

Front 55

verbose command

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-v

Front 56

Use the ls -l (list long) command before

Back 56

compressing a file to see its original size in bytes

Front 57

The corresponding command used to reverse the effects of the compress command is

Back 57

uncompress

Front 58

The uncompress command is a UNIX utility and can be used only to

Back 58

uncompress files compressed with the UNIX compress command

Front 59

to view the contents of the june02bkup.tar.Z compressed file, use the following command:

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uncompress -c june02bkup.tar.Z | more

Front 60

To restore files from a tape archive

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1) Make a new directory and change to it 2) Extract the home directory from tape 3) Uncompress the compressed tar file 4) Extract the tar file 5) Moves files as needed

Front 61

GNU provides several commands that can supplement the

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tar and jarcommands

Front 62

The gzip utility is a popular

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open source tool for combining and compressing files

Front 63

The GNU tar command supports

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compression

Front 64

The -z option compresses with gzip and -Z compresses using the

Back 64

compress command

Front 65

tar -cvzf /temp/bkup.tar /home/user2 will use the

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gzip command to create a compressed bkup.tar file of the user2 directory tree

Front 66

Another feature GNU tar supports is the ability to span a

Back 66

backup across multiple (-M) volumes, whether disks or tapes

Front 67

Due to the popularity of the PKZIP and WinZip programs used in the DOS and Windows worlds, there are now UNIX versions that work in

Back 67

the same way and can read files zipped on a PC

Front 68

The zip command is similar to the

Back 68

jar command and is capable of compressing multiple files into a single zip file

Front 69

The unzip command is used to

Back 69

uncompress a file created with zip

Front 70

If the version of UNIX that the student is using does not have the zip command, the student should do an

Back 70

Internet search to locate a download site

Front 71

cpio Command Option: o

Back 71

Creates a file archive. Copies a list of files or pathnames to a file or a device (copy out).

Front 72

cpio Command Option: l

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Extracts the file archive from the device or file (copy in).

Front 73

cpio Command Option: p

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Reads from the file or device to get pathnames.

Front 74

cpio Command Option: t

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List the table of contents of the device without restoring the files.

Front 75

cpio Command Option: v

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Executes in verbose mode displaying each file name to the screen.

Front 76

cpio Command Option: O

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Directs the output to a file.

Front 77

cpio Command Option: I

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Read the contents of a file as an input archive.

Front 78

Features of Dedicated Backup Applications

Back 78

-Designed specifically to work with various backup media

-More flexibility with scheduling of backups

-Graphical user interface

-Drag and drop capabilities for backup and restore