File system

Question 1

What is the find option for selecting files accessed n minutes ago?

Answer 1

-amin n

Question 2

What is the find option for selecting a file accessed one day or more ago?

Answer 2

find -atime n (where n is n*24 hours ago. -atime +1 is a file that was accessed at least two days ago)

Question 3

what find option will select a file changed n minutes ago?

Answer 3

find -cmin n

Question 4

what find option will display the results?

Answer 4

find -print

Question 5

what is a simple example of find to locate a wild card file name?

Answer 5

find . -name thename*.dat -print

start the search in the current directory .

use the name mask “thename*.dat”

print out the results to the screen

Question 6

what is a find command to locate all core files and then remove them?

Answer 6

find / -name core -exec /bin/rm -f ‘{}’ \;

start in the root directory

use “core” as the name filter

execute the rm command

force the removal without prompting -f

pass the rm command the file name found ‘{}’ \;

Question 7

What is the find option for selecting files accessed n minutes ago?

Answer 7

-amin n

Question 8

What is the find option for selecting a file accessed one day or more ago?

Answer 8

find -atime n (where n is n*24 hours ago. -atime +1 is a file that was accessed at least two days ago)

Question 9

what find option will select a file changed n minutes ago?

Answer 9

find -cmin n

Question 10

what find option will display the results?

Answer 10

find -print

Question 11

what is a simple example of find to locate a wild card file name?

Answer 11

find . -name thename*.dat -print

start the search in the current directory .

use the name mask “thename*.dat”

print out the results to the screen

Question 12

what is a find command to locate all core files and then remove them?

Answer 12

find / -name core -exec /bin/rm -f ‘{}’ \;

start in the root directory

use “core” as the name filter

execute the rm command

force the removal without prompting -f

pass the rm command the file name found ‘{}’ \;

Question 13

how do you set the sticky bit on an existing directory structure?

Answer 13

find /path/to/directory -type d -exec chmod g+s {} \;

This will recurse through the entire directory structure settingh the GID on all the directory objects (not the files) to the SETGID of the owner of the parent directory. All files created subsequently, will inherit the same GID of the parent directory instead of the default GID of the user who created the file.

Question 14

what are the daemons used by nfs?

Answer 14

nfsd

rpcbind

rpc. idmapd
rpc. mountd
rpc. rquotad
rpc. statd

Question 15

what is the tar command for copying an entire directory tree including the file permissions and links?

Answer 15

tar -cf - {source} | (cd {destination}; tar -xvf -)

Question 16

Traverse the filesystem just once, listing setuid files and directories into /root/suid.txt and large files into /root/big.txt.

Answer 16

find / ( -perm -4000 -fprintf /root/suid.txt ‘%#m %u %p\n’ ), \
( -size +100M -fprintf /root/big.txt ‘%-10s %p\n’ )

Question 17

what command will show the server’s current exports?

Answer 17

showmount -e

Question 18

what command will list the users who have a file open?

Answer 18

lsof {filename}

Question 19

what command will show the PID of the process that has a file open?

Answer 19

fuser {filename}

Question 20

what command is used to change the system run level?

Answer 20

init { 0 1 2 3 4 5 6 }

0 — Halt

1 — Single-user text mode

2 — Multiuser but no NFS

3 — Full multi-user text mode

4 — Not used (user-definable)

5 — Full multi-user with X11

6 — Reboot

Question 21

what command shows the current run level?

Answer 21

who -r

Question 22

what file defines the default run level?

Answer 22

/etc/inittab

Question 23

what tools are provided by redhat to configure services?

Answer 23

chkconfig

ntsysv

redhat-config-services

Question 24

how do you locate all broken symlinks?

Answer 24

find / -name proc -prune -o -name dev -prune -o -type l ! -exec test -r {} \; -print

Question 25

how do you backup the MBR?

Answer 25

sudo dd if=/dev/sda of=mbr_backup bs=512 count=1

to restore it:

sudo dd if=mbr_backup of=/dev/sda bs=512 count=1

Question 26

what are the sequence of commands for creating a new partition?

Answer 26

create partition:
parted /dev/sda6 or mkpart for ext3

create filesystem:
mkfs -t ext4 /dev/sda6

*label it: *
e2label /dev/sda6 /work

add to fstab:
LABEL=/work /work ext3 defaults 1 2

**mount it: **
mount /work

Question 27

what command will show the UUID of the block or disk drives?

Answer 27

blkid

Question 28

what are the standard default options for fstab?

Answer 28

if the options field ( fourth column ) says “defaults”,

the usual values are:

rw,
suid,
dev,
exec,
auto,
nouser,
async(no acl support)

this can also be tuned with the tune2fs command.

Question 29

what commands are used to create partitions?

Answer 29

fdisk

sfdisk

cfdisk

parted

Question 30

what command script string will show all physical drives and their partitions if any?

Answer 30

for disk in ls /dev/sd[a-z]; do fdisk -l ${disk}; done

Question 31

what command is used to add a physical volume to a volume group?

Answer 31

vgextend <volgroupname> <pv></pv></volgroupname>

Question 32

what command is used to remove a pv from a vg?

Answer 32

vgreduce <vgname> <pvname></pvname></vgname>