Sec. 40 Backup and Recovery Methods

Question 1

cpio and tar

Answer 1

cpio and tar create and extract archives of files .

Question 2

gzip, bzip2, and xz

Answer 2

Archives are often compressed with gzip, bzip, or xz. the archive file may be written to disk , magnetic tape, or any other device which can hold files.
Archives are very useful for transferring files from on filesystem or machine to another.

Question 3

dd

Answer 3

dd -this powerfull utility is often used to transfer raw data between media. it can copy entire partitions or hard disks .

Question 4

rsync

Answer 4

rsync - this powerful utility can synchronize directory subtrees or entire filesystems across a network, or between different filesystems locations on a local machine.

Question 5

mt

Answer 5

mt - this utility is useful for querying and positioning tapes before performing backups and restores.

Question 6

Describe some of tar commands features :

Answer 6

• when creating a tar archive, for each directory given as an arguement, all files and subdirectories will be included in the archive.
• when restoring, it reconstitutes directories as necessary.
• it even has a –newer option that lets you do incremental backups
• the version of tar used in linux can also handle backups that do no fit on one tape or whatever device you use.

Question 7

tar

Answer 7

-arg - directory

-description: for each directory given, all files and subdirectories will be included in the archive.

Question 8

when restoring tar, it reconstitutes ….?

Answer 8

when restoring tar , it reconstitutes the directories as necessary.

Question 9

tar even has a –newer option that …….?

Answer 9

tar even has a –newer option that lets you do incremental backups

Question 10

by default tar will recursively …….?

Answer 10

by default tar will recursively include all subdirectories in the archive.

Question 11

archive

Answer 11

an archive is a file that contains the contents fo many files , while still identifying the names of the files , their owners and so forth.

-in addition archives records access permissions , user, and group , size in bytes, and data modification time.

Question 12

the files in archives are called ……?

Answer 12

memebers

Question 13

the term extraction refers to the process of copying an archive member (or multiple members) into a file in the file system.

Answer 13

Extracting all the memebers of an archive is often call extracting the archive.

or unpacking the archive.

Question 14

what does the term extraction refer to w.r.t. archives ?

Answer 14

the term extraction refers to the process of copying an archive member or multiple members into a file in the file system.

Question 15

extracting an archive does not destroy the archive’s structure, just as creating an archive does not destroy the copies of hte files that exist outside the archive.

Answer 15

You may list the members in a given archive, or append members to a pre-existing archive.

Question 16

the tar program provides teh abiltiy to create tar archives, as well as varius other kinds of manipulation.

Answer 16

You can use tar archives in many ways. there are three important ones: storage, backup, and transportation.

Question 17

conventionally , tar archives are given names that end with …..?

Answer 17

.tar

Question 18

what are three main options of the tar program?

Answer 18

1. –create
2. –list
3. –extract

Question 19

the main types of arguements of the tar fall inot one of two classes. what are they?

Answer 19

1. operations
2. options

Question 20

w.r.t tar am I required to specify options?

Answer 20

no

Question 21

Can i specify more than one operation with tar?

Answer 21

no

Question 22

tar –create or tar -c

Answer 22

create a new tar archive

Question 23

tar –list or tar -t

Answer 23

list the contents of an archive

Question 24

tar –extract or tar -x

Answer 24

extract one or more members from an archive.

Question 25

**tar --file=archive-name** or **tar -f archive-name**

Answer 25

specify the name of an archive file

Question 26

**tar** *--verbose* or **tar** *-v*

Answer 26

show the files being worked on as **tar** is running

Question 27

if I want to see the progress of **tar** as it writes files into the archive , I can use what option?

Answer 27

*--verbose*

Question 28

when reading archives , **tar** by default prints only the names of the members being extracted.

Answer 28

when writing archives **tar** does not print file names by default.

Question 29

**tar** *--same-permissions* or **tar** *-p*

Answer 29

ensures files are restored with their original permissions.

Question 30

**tar -x** or **tar --extract**

Answer 30

extracts members from a archive, all by default. I can narrow the list to only specify specific files . if a **directory** is specified, than all included files and subdirectories will are also extracted.

Question 31

what must I specify when creating an archive?

Answer 31

what/which files I want placed in the archive.

Question 32

is the **--file=file\_name.tar** considered one arguement or two ?

Answer 32

one

Question 33

**tar** always sees its first arguement as an _________ ?

Answer 33

option

Question 34

when using **tar** and using the long options is order important?

Answer 34

no

Question 35

when does the order of the options become more important?

Answer 35

when using the short options versions.

Question 36

when creating an archive using **tar** does it destroy the orginal files ?

Answer 36

no

Question 37

what **access** would i need to the working directory in order to create an archive in that directory.

Answer 37

write access

Question 38

what would happen if i did the following: $ **tar --create --file=collection.tar jazz** and the archive collection.tar already existed.

Answer 38

the orginal **collection.tar** would be overwritten

Question 39

If I would like to add files to an already esixting archive what option would I use?

Answer 39

**--append** ; **-r** instead of the option **--create, -c**

Question 40

How would I archive a directory?

Answer 40

by specifing the directory name as the filename arguement in **tar.**

Question 41

where is the archive placed when **tar** program is invoked?

Answer 41

in the directory that **tar** was invoked.

Question 42

what is the short version of the **--list** option for **tar**?

Answer 42

**-t**

Question 43

I can force GNU **tar** to show member names when creating an archive by using what option?

Answer 43

**--show-stored-names**

Question 44

with what option can I do incremental backups using **tar**?

Answer 44

**--newer** ; **-N**

Question 45

when ever I use the option **--newer** or **-N**. I need to specify one of two things. what are they?

Answer 45

1. a date or 2. a qualified file name.

Question 46

**rsync** has the ability when copying files from on directories, it will only \_\_\_\_\_\_\_\_ will be copied over.

Answer 46

differences

Question 47

**gzip**

Answer 47

uses lempel-ziv coding (LZ77 ) and produces **.giz** files

Question 48

**bzip**

Answer 48

uses *burrows-wheeler* block sorting text compression algorithim and huffman coding and produces **.bz2** files .

Question 49

do decompression times vary as much as compression times ?

Answer 49

no

Question 50

what is rarely used w.r.t. file compression?

Answer 50

**.zip** files

Question 51

How would use compression at the same time as **tar** w.r.t. the following example: $**tar zcvf source.tar source.**

Answer 51

**$ tar zcvf source.tar.gz source**

Question 52

can **compression** and **archiving** happen at the same time?

Answer 52

yes.

Question 53

it is often desired to compress files to save......?

Answer 53

1. diskspace and or 2. lower network transmission time.

Question 54

modern machines would find the process of \_\_\_\_\_\_\_\_\_\_\_\_\_-\_\_\_\_\_\_\_\_\_\_-\_\_\_\_\_\_\_\_\_\_ faster than transmiting uncompressed files

Answer 54

**compress - transmit-decompress**

Question 55

For larger files what two compression utilities are used ?

Answer 55

1. **bzip2** or 2. **zx**

Question 56

For smaller files what compressing utility is used?

Answer 56

**gzip**

Question 57

If I wanted to create a 10mb file filled with zeros what would I do w/ **dd?**

Answer 57

**$ dd if=/dev/zero of=outfile bs=1M count=10**

Question 58

**dd** is one of the _________ \_\_\_\_\_\_\_\_ and is \_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_

Answer 58

**dd** is one of the orginal unix utilities and is extermely versatile.

Question 59

Using **dd** how would I create a backup for **/dev/sda1**?

Answer 59

$ **dd if=/dev/sda1 of=partition1.img**