Create and Configure File Systems

Question 1

to create a file system

Answer 1

use mkfs(may ways to use it depending on the file system type, ie)
# mkfs -t ext4 /dev/sdb1
# mkfs.ext4 /dev/sdb1

Question 2

tune2fs

Answer 2

helps us control how many times a filesystem can be mounted before a filesystem check needs to run on it.

Command to run after you've formatted a partition
#tune2fs -m0 /dev/sdb1

Question 3

check info on a filesystem

Answer 3

tune2fs -l /dev/sdb1

Question 4

check a filesystem

Answer 4

fsck /dev/sdb1 do not run on a mounted filesystem

Question 5

to create an xfs filesystem

Answer 5

mkfs.xfs /dev/sdb2

Question 6

to create a vfat filesystem

Answer 6

mkfs.vfat /dev/sdb3

Question 7

To get details about a file system type

Answer 7

dumpe2fs /dev/sdb2

Question 8

to repair an unmounted filesystem consistency (xfs filesystem)

Answer 8

xfs_repair /dev/sdb2

Question 9

to get details about a mount xfs filesystem

Answer 9

xfs_info /dev/sdb2

Question 10

to repair an unmounted vfat filesystem

Answer 10

fsck.vfat /dev/sdb3

Question 11

steps to mount a filesystem

Answer 11

1 - create a directory
#mkdir /mnt/data
2. mount the filesystem
# mount -t ext4 /dev/sdb1 /mnt/data
3. check that it's mounted
# mount | grep data
4. add entry to /etc/fstab to mount after reboot(permanent)

Question 12

What’s needed to mount an NFS(network file system) filesystem

Answer 12

First you need to install
# yum -y install nfs-utils nfs-utils-lib
Then you need to start the right services
# service nfs start
# service rpcbind start
Afterward add them to start at boot
# chkconfig nfs on
#chkconfig --level 35 rpcbind on

Question 13

show which nfs filesystem is available on a system

Answer 13

showmount -e [ip or hostname]

Question 14

mount nfs to a local directory

Answer 14

# mkdir /mnt/nfs
# mount -t nfs ip:/srv/nfs /mnt/nfs   you could also put hostname instead of ip
For permanent entry add to /etc/fstab
name:/srv/nfs    /mnt/nfs    nfs   _netdev    0 0

Question 15

for nfs use _netdev instead of defaults

Answer 15

It tells the mount command to wait for the network services to come up prior to mounting the share(to prevent hanging)

Question 16

for CIFS network file system (common Internet File System)

Answer 16

Install the samba client packages
#yum install -y cifs-utils
# yum install -y samba-client

Question 17

Cifs permanent mounting

Answer 17

//smbserver/shared /mnt cifs rw,user,credentials=/root/secret.txt 0 0

in /root/secret.txt add
username=visitor
password=Welcome123$

Question 18

to see which shares are available on a cifs server

Answer 18

smbclient -U username -L [hostname/IP]

Question 19

To login to the remote cifs share

Answer 19

smbclient -U username //ip/shared

Question 20

You can run windows command when you’ve logged into a cifs shared

Answer 20

smb: > get filename.txt download a file
smb: > put file1.txt upload a file

Question 21

To mount a cifs share(temporarily)

Answer 21

mount -t cifs -o user-[username] //IP-or-host/shared /mnt/shared
review man mount.cifs
You can also do it from the desktop
Go to Places -> connect to server
Change the service type to window share, enter info, then click connect

Question 22

To increase the size of a logical volue

Answer 22

use the lvextend command. When you extend the logical volume, yo ucan indicate how much to extend the volume, or how large you want it to be after you extend it.

Question 23

The following command extends the logical volume /dev/myvg/homevol to 12GB

Answer 23

lvextend -L 12G /dev/myvg/homevol

Question 24

The following command adds another gigabyte to the logical volume

Answer 24

lvextend -L +1G /dev/myvg/homevol

Question 25

The following command extends the logical volume called testlv to fill all of the unallocated space in the volume group myvg

Answer 25

#lvextend -l +100% Free /dev/myvg/testlv

Question 26

adding a filesystem on a logical volume

Answer 26

``` #mkfs.ext4 /dev/vg_new/lv_new #mkdir /extra directory to mount logical volume add entry to /etc/fstab /dev/vg_new/lv_new /extra ext4 defaults 0 0 # mount -a ```

Question 27

To grow the logival volume lvresize can also be used

Answer 27

``` #lvresize -L 900M /dev/vg_new/lv_new Then resize the filesystem # resize2fs /dev/vg_new/lv_new ```

Question 28

To shrink the logical volume(make sure to have a backup)

Answer 28

``` #unmount extra #fsck -f /dev/vg_new/lv_new #resize2fs /dev/vg_new/lv_new 800MB #lvresize -L 800MB /dev/vg_new/lv_new ```

Question 29

Set-GID

Answer 29

set-gid directories are used for group collaboration. Everything that is created in a directory with that special permission bit, is automatically owned by the group

Question 30

how to apply the set-git permission

Answer 30

applying the set-git permission on a directory by add a 2 before the standard permission set # chmod 2755 share -Then you'll see the directory has a permission set that contains a 's' now in place of the x for group -the character based way to setup a set-gid directory #chmod g+s share

Question 31

ACL(Access Control Lists)

Answer 31

- to use AACLs first the acl property needs to be enabled on the partition. run the mount command to check # mount - to change and turn on ACL make changes in /etc/fstab before /dev/mapper/vg_rhel01/lv_root / ext4 defaults 1 1 after /dev/mapper/vg_rhel01/lv_root / ext4 defaults,acl 1 1 Then you need to remount or restart to remount # mount -o remount / Without adding entry to fstab(this isn't permanent) # mount -o remount -o acl /dev/...

Question 32

to check acl on a directory or file

Answer 32

``` use the getfacl command #getfacl file ```

Question 33

to add user acl to a file or directory

Answer 33

setfacl -m u:user2:rw install.log m = modify

Question 34

to add a group acl on a file

Answer 34

#setfacl -m g:IT:rwx install.log

Question 35

to remove all acls on a file

Answer 35

#setfacl -b file1 -b for remove all

Question 36

Note pay attention to "other" users in regard to ACL

Answer 36

``` #setfacl -m o:rwx file1 gives rwx to other, but you cannot use -x or -b to remobe such a change. The only way to remove this acl is either the follwoing command: #setfacl -m o:www file1 or #chmod o-rwx file1 ```

Question 37

to remove permissions allowed to the user bob(-x for remove)

Answer 37

#setfacl -x u:bob file1

Question 38

Apply ACL recursively

Answer 38

#setfacl -R -m u:user1:rwx file1

Question 39

The following command cancels ACL settings for a user recursively

Answer 39

#setfacl -R -x u:user1 file1

Question 40

The mask in regard to ACL

Answer 40

``` The mask associated with ACL limits the permission available on a file. In other words, with a mask of --r, you can try all other privileges, but all that can be set with that mask is read privileges. The command to set the mask: #setfacl -m mask:r-- acltest.txt ```

Question 41

To set a default ACL

Answer 41

``` Add d: before the rule and specify a directory instead of a filename #setfacl -m d:o:rx /share ```

Question 42

Man in regard to ACL

Answer 42

``` review these man pages #man acl #man getfacl #man setfacl #man star the star utility ```