Linux, CCNA and MCSE Questions: Logical Volume Management and RAID Levels

1. What is LVM and why we go for LVM?

Lvm means Logical Volume Management. The combination of 2 or more physical disk in order to make a big logical disk is called Logical Volume.

If normal Linux partition is full and an application requires some more disk space, then normal partition cannot be extended for that application requirement. For this first we have to take a backup of that normal partition, delete that partition and again create that partition with more disk space, format and mount that partition and finally restore the application from the backup. This process requires down time.

So, to overcome this problem LVM concept is coming into the picture. Using this LVM we can extend or reduce the file systems as per requirement without loss of any data.

2. What are the components of the LVM?

Physical Volume (PV)

Physical Extent (PE)

Volume Group (VG)

Logical Volume (LV)

Logical Extent (LE)

Physical Volume (PV) :

It is the standard partition that we add to the LVM. Normally a physical volume is a standard primary or logical partition with the partition code as 8e.

Physical Extent (PE) :

It is chunk of disk space. Every physical volume is divided into a number of equal sized PEs.

Volume Group (VG) :

It is composed of a group of physical volumes and logical volumes. It is the organizational group of LVM.

Logical Volume (LV) :

It is composed of a group of LEs. We can format (make a file system) and mount any file system on the logical volume. The size of these logical volumes can easily be increased or decreased as per the requirement.

Logical Extent (LE) :

It is also a chunk of disk space. Every logical extent is mapped to a specific physical extent.

3. How to create the LVM, make a file system and mount that permanently?

(i) Take two physical disks for example /dev/sdb and /dev/sdc. if there is no second disk then make the required partitions using # fdisk command and change the partition code as 8e.

(ii) Convert the Physical disk into physical volumes by,

# pvcreate /dev/sdb /dev/sdc

(iii) Then create the volume group by combining physical volumes by,

# vgcreate or

# vgcreate -s

(iv) Then create the logical volume on the above created volume group by,

# lvcreate -L + -n or

# lvcreate -l -n

(v) Make a file system on the above created logical volume by,

# mkfs.ext2/ext3/ext4/xfs /dev//

(vi) Create a mount point to mount the above created LVM file system by,

# mkdir /mnt/

(vii) Mount the LVM on the above created mount point temporarily by,

# mount /dev//or

Mount the LVM on mount point permanently by,

# vim /etc/fstab

/dev// /mnt/ defaults 0 0

Esc+:+wq!

# mount -a

# df -hT (to see the mounted partitions with file system types)

4. How to see the details of the Physical Volumes?

# pvs (displays all physical volumes with less details)

# pvdisplay (displays all physical volumes with more details)

# pvdisplay (displays the details of the specified physical volume)

# pvscan (to scan all the physical volumes)

#pvscan (to scan the specified physical volume)

5. How to see the details of the Volume Groups?

# vgs (displays all volume groups with less details)

# vgdisplay (displays all volume groups with more details)

# vgdisplay (displays the specified volume group with more details)

# vgscan (to scan all the volume groups)

# vgscan (to scan the specified volume group)

6. How to see the details of the Logical Volumes?

# lvs (displays all logical volumes with less details)

# lvdisplay (displays all logical volumes with more details)

# lvdisplay (displays the specified logical volume details)

# lvscan (to scan all the logical volumes)

# lvscan (to scan the specified logical volume)

7. How to extend the Volume Group?

Extending the volume group is actually adding a new physical volume to the volume group.

To extend the volume group we need to create a new partition using # fdisk command and make sure that it's partition id should be 8e, save the changes and update the partition table by # partprobe

Create a physical volume on the newly created partition using # pvcreate command.

Add the partition to the volume group using # vgextend command

Example : # fdisk /dev/sdb

Command (m for help) : n

First cylinder : press Enter for default one

Last cylinder : +500M (create 500MB partition)

Command (m for help) : t (to change the partition id)

Select the partition : type the partition number

Specify the Hexa code : 8e

Command (m for help) : w (to save the changes)

# partprobe /dev/sdb1

# pvcreate /dev/sdb1

# vgextend /dev/sdb1

# vgdisplay (to check the size of the volume group)

8. How to extend the logical volume and update it's file system?

Sometimes the file system size may be full, so we need to increase the size of the logical volume to continue adding the data in it.

The size of the logical volume can be increased online, no downtime required.

Check current size of the logical volume by # lvdisplay and the size of the file system by # df -hT command.

Increase the size of the logical volume by # lvextend or # lvresize commands.

Then finally update the file system by # resize2fs or # xfs_growfs commands.

Example : # df -hT

# lvextend -L +

# lvresize -L +

# resize2fs

# lvdisplay

(to check the size of the logical volume)

# df -hT (to check the size of the file system)

9. How to reduce the logical volume and update the file system?

Reducing the size of the logical volume is a complicated task and we have remember some points before reducing the logical volume, otherwise the file system may be damaged .

Logical volume size cannot be reduced online and it requires downtime because we have to unmount the file system by # umount command.

Check the consistency of the file system by # e2fsck command.

Reduce the logical volume by # lvreduce -L -

command.

Then update the file system by # resize2fs

Finally mount the file system by # mount -a

Example : # umount

# e2fsck

# lvreduce -L -

# resize2fs

# lvdisplay

(to check the size of the logical volume>

# mount -a (to mount the file system)

# df -hT (to check the size of the file system)

10. How to move or migrate the logical volume data from one physical volume to another physical volume?

There might be a situation where the physical volume might be failing and it is required to replaced. In such case, we need to migrate or move the logical volume data from the failed physical volume new physical volume and isolate (remove) the failed physical volume.

First access the mount point of the failing physical volume and check the data in it.

Verify the size of the physical volume by #pvs or #pvdisplay

command.

Unmount the file system of that physical volume by # umount

Add a new physical volume and the size should be same size or higher than that failing physical volume.

Migrate the physical volume contents to the new physical volume using # pvmove

Mount back the logical volume, access the mount point and verify the data in it.

Remove the failed the physical volume by #vgreduce command.

Example : # cd

# ls

# pvs or # pvdisplay

# umount

# pvcreate

#vgextend

# pvmove

# mount -a

# vgreduce

# cd

# ls

11. How to delete or remove the logical volume?

To delete or remove the logical volume, first unmount the file system by # umount

Remove the entry in /etc/fstab file.

Remove the logical volume by # lvremove

command.

Verify whether the logical volume is removed or not by # lvs or # lvdisplay command.

Example : # umount

# vim /etc/fstab (delete the entry of the logical volume)

Esc+:+wq! (save and exit the file)

# lvremove

# lvs or # lvdisplay (to verify whether logical volume is removed or not)

12. How to delete or remove the volume group?

To delete or remove the volume group, first make sure that any logical volume should not be mounted because while removing a volume group it will delete or remove the logical volumes in that volume group.

Then delete or remove the volume group by # vgremove command.

Verify whether the volume group is remove or not by # vgs or # vgdisplay command.

Example : # umount (to unmount the file system if there is any LV)

# vim /etc/fstab (delete the entry of the logical volume)

Esc+:+wq! (save and exit the file)

# vgremove

# vgs or # vgdisplay (to verify whether volume group is removed or not)

13. How to delete or remove the physical volume?

Deleting or removing a physical volume is very simple and the only thing we should check that the physical volume we are going to delete should not belong to any volume group ie., we can only delete or remove the physical volume which is free.

Then delete or remove the physical volume by # pvremove command.

Verify whether the physical volume is removed or not by # pvs or #pvdisplay command.

Example : # pvremove

# pvs or #pvdisplay (to verify whether the physical volume is removed or not)

14. How to restore the volume group which is removed mistakenly?

First unmount file system by # umount command.

Check the volume group backup list by # vgcfgrestore --list command.

Then remove the logical volume by # lvremove

command.

Copy the backup file which is taken backup before removed the volume group from the above backup list and paste it in this command # vgcfgrestore -f

The logical volume is created automatically after restoring the volume group but the volume group and logical volumes both will be in inactive state. So, check the state of the volume group by #vgscanand the logical volume state by # lvscan commands.

Then activate that volume group by # vgchange -ay commandand activate the logical volume by # lvchange -ay command.

Mount the logical volume file system by # mount -a command.

Example : # umount

# vgcfgrestore --list (copy the backup file from the list)

# lvremove

# vgcfgrestore -f

# vgscan (to check the status of the volume group)

# lvscan (to check the status of the logical volume)

# vgchange -ay (activate the volume group if it is in inactive state)

# lvchange -ay (activate the logical volume if it is in inactive state)

Note: The option a means active VG or LV and option y means yes.

# mount -a

15. How to change the volume group name and other parameters?

# vgrename (to rename the volume group)

By default, unlimited logical volumes can be created per volume group. But we can control this limit by

# vgchange -l (to limit max. no. of logical volumes to the specified number)

Example : # vgchange -l 2 (to limit max. 2 logical volumes cab be created in this volume group)

# vgchange -p (to limit max. no. of physical volumes to the specified number)

Example : # vgchange -p 2 (to limit max. 2 physical volumes can be added to this volume group)

# vgchange -s (to change the block size of the volume group)

Example : # vgchange -s 4 (to change the volume group block size to 4MB)

16. How to change the logical volume name and other parameters?

# lvrename (to rename the logical volume)

# lvchange -pr (to put the logical volume into read only mode)

# lvs (to see the logical volume permissions)

# lvchange -prw (to put the logical volume into read and write mode)

17. How to disable the volume group and logical volume?

# vgchange -an (to disable the volume group)

# lvchange -an (to disable the logical volume)

18. How to take a backup of the volume group?

# vgcfgbackup (to take a backup of all volume groups)

# vgcfgbackup (to take a backup of the specified volume group)

19. What is the configuration file of the logical volume?

# cat /etc/lvm/lvm.conf (to see the contents of the LVM configuration file)

20. What are the locations of the logical volume and volume groups?

# cd /etc/lvm/backup (the logical volumes backup location)

# cd /etc/lvm/archive (the volume groups backup location)

21. How to know the current version of the LVM package?

# rpm -qa lvm* (to know the current version of the LVM package)

22. What are the attributes of the volume group?

# vgs (to see the attributes of the volume group)

[ The attributes are w ----> writable z ----> extendable n ----> normal ]

# vgs -v (to check the UUID of the volume group)

23. How to extend the logical volume to max. disk space and half of the disk space?

# lvextend -l +100% FREE (to extend the logical volume by adding the

volume group's total available space)

# lvextend -l 50% (to extend the logical volume by adding the 50%

free space of the volume group)

24. How to check on which physical volume the data is writing in the logical volume?

# lvdisplay -m ( to check on which physical volume the data is currently writing from all logical volumes)

# lvdisplay -m (to check on which physical volume the data is writing from the

Specified logical volume)

25. How many types of file systems available?

ext2 ---->Second extended file system (default in RHEL - 3 & 4)

ext3 ---->Third extended file system (default in RHEL - 5)

ext4 ----> Fourth extended file system (default in RHEL - 6)

xfs ----> Extended file system (default in RHEL - 7)

ufs ----> Unix file system (default in Solaris)

jfs ----> Journal file system (default in IBM-AIX)

hfs ----> High performance file system (default in HP-UX)

vxfs ----> Veritas file system

procfs ----> Process file system (temporary)

tempfs ----> Temporary file system (temporary)

cdfs ----> Compact disk file system

hdfs ----> DVD file system

iso9660 ----> To read the CD/DVD.iso image format files in Linux

26. How to scan and detect the luns over the network?

# ls /sys/class/fc_host (to check the available fibre channels)

# echo "---" > /sys/class/scsi_host//scan (to scan and detect the luns over the network)

27. How to mount a pen drive in Linux?

# lsusb or # fdisk -l (to know the pen drive name)

# mkdir /mnt/pendrive (to create a mount point for pen drive)

# mount ( to mount the pen drive on the above created mount

point)

# cd /mnt/pendrive (to access the pen drive)

28. How to mount a CD/DVD ROM drives in Linux?

The CD/DVD ROM device name in Linux is /dev/cdrom

# mkdir /mnt/mycdrom (to create the mount point for CD/DVD)

# mount /dev/cdrom /mnt/mycdrom (to mount the CD/DVD on the above created mount point)

# cd /mnt/mycdrom (to access the CD/DVD ROM drives)

29. How to mount the " .iso " image files in Linux?

# mount -t iso9660 /root/rhel6.iso /iso -o ro, loop (to mount the .iso image files)

# cdrecord /root/Desktop/rhel6.iso (to write the CD/DVD ROM. Before executing this

command put the empty CD/DVD into CD/DVD drive)

# eject (to eject the CD/DVD drive tray)

# eject -t (to insert and close the CD/DVD drive tray)

30. What is RAID? What is the use of the RAID and how many types of RAIDs available?

RAID stands for Redundant Array of Independent Disks.

It provides fault tolerance, load balancing using stripping, mirroring and parity concepts.

There are mainly two types of RAIDs available.

(i) Hardware RAID (Depends on vendors and also more expensive)

(ii) Software RAID (Does not depends on vendors and less expensive when compared to Hardware

RAID and also it is maintained by system administrator only.

31. How many types of software RAIDs available and their requirements?

(i) RAID - 0 ---- Stripping ---- Minimum 2 disks required

(ii) RAID - 1 ---- Mirroring ---- Minimum 2 disks required

(iii) RAID - (1+0) --- Mirroring + Stripping ---- Minimum 4 disks required

(iv) RAID - (0+1) --- Stripping + Mirroring ---- Minimum 4 disks required

(v) RAID - 5 ---- Stripping with parity ---- Minimum 3 disks required

32. How to configure RAID - 0 in Linux?

To configure RAID - 0, minimum 2 disks are required and the partition id is "fd".

Reading and writing is very fast. So, it produces high performance.

if one disk is failed we cannot recover the data.

So, there is no redundancy and fault tolerance in RAID - 0.

Example : For example if the data is 1, 2, 3, 4, 5 and 6 then ....

Disk - 1 Disk - 2

If the Disk - 1 is /dev/sdb and the Disk - 2 is /dev/sdc then,

# mdadm -Cv /dev/md0 -n 2 /dev/sdb /dev/sdc -l 0 (to create the RAID - 0 using disk - 1 and disk - 2)

# cat /proc/mdstat (to check the RAID - 0 is created or not)

# mkfs.ext4 /dev/md0 (to create the ext4 file system on the RAID - 0)

# mkdir /mnt/raid0 (to create the RAID - 0 mount point)

# mount /dev/md0 /mnt/raid0 (to mount RAID - 0 on the mount point)

# mdadm -D /dev/md0 (to see the details of the RAID - 0 partition)

# mdadm /dev/md0 -f /dev/sdb (to failed the disk manually)

# mdadm /dev/md0 -r /dev/sdb (to remove the above failed disk)

# mdadm /dev/md0 -a /dev/sdd (to add the new disk in place of failed disk)

# umount /mnt/raid0 (to unmount the raid file system)

# mdadm --stop /dev/md0 (to stop the RAID - 0 volume)

# mdadm /dev/md0 --add /dev/sde (to add third disk to the RAID - 0 volume)

# mdadm --grow /dev/md0 --raid_device=3 (to grow the RAID - 0 file system)

33. How to configure RAID - 1 in Linux?

To configure RAID - 1, minimum 2 disks are required and the partition id is "fd".

In this the same data will be written on 2 disks ie., exact copy on both the disks.

if one disk is failed we can recover the data from another disk.

So, there is a high availability, redundancy and fault tolerance in RAID - 1.

In this writing speed is slow compared to RAID - 0.

Example : For example if the data is 1, 2, 3, 4, 5 and 6 then ....

Disk - 1 Disk - 2

If the Disk - 1 is /dev/sdb and the Disk - 2 is /dev/sdc then,

# mdadm -Cv /dev/md0 -n 2 /dev/sdb /dev/sdc -l 1 (to create the RAID - 1 using disk - 1 and disk - 2)

# cat /proc/mdstat (to check the RAID - 1 is created or not)

# mkfs.ext4 /dev/md0 (to create the ext4 file system on the RAID - 1)

# mkdir /mnt/raid1 (to create the RAID - 1 mount point)

# mount /dev/md0 /mnt/raid1 (to mount RAID - 1 on the mount point)

# mdadm -D /dev/md0 (to see the details of the RAID - 1 partition)

# mdadm /dev/md0 -f /dev/sdb (to failed the disk manually)

# mdadm /dev/md0 -r /dev/sdb (to remove the above failed disk)

# mdadm /dev/md0 -a /dev/sdd (to add the new disk in place of failed disk)

# umount /mnt/raid1 (to unmount the raid file system)

# mdadm --stop /dev/md0 (to stop the RAID - 1 volume)

# mdadm /dev/md0 --add /dev/sde (to add third disk to the RAID - 1 volume)

# mdadm --grow /dev/md0 --raid_device=3 (to grow the RAID - 1 file system)

34. How to configure RAID - 5 in Linux?

To configure RAID - 5, minimum 3 disks are required and the partition id is "fd".

In every disk approximately 25 - 30% of space is reserved for parity.

Reading and writing is very fast. So, it produces high performance.

This is used Stripping with parity concept.

if one disk is failed we can recover the data using remaining two disks and parity.

If two disks are failed, then we cannot recover the data.

So, there is no redundancy and fault tolerance in RAID - 5.

Example : For example if the data is 1, 2, 3, 4, 5 and 6 then ....

3+4

5+6

1+2

Disk - 1 Disk - 2 Disk - 3

If the Disk - 1 is /dev/sdb, the Disk - 2 is /dev/sdc and Disk - 3 is /dev/sddthen,

# mdadm -Cv /dev/md0 -n 2 /dev/sdb /dev/sdc -l 5 (to create the RAID - 5 using disks - 1, 2 and 3)

# cat /proc/mdstat (to check the RAID - 5 is created or not)

# mkfs.ext4 /dev/md0 (to create the ext4 file system on the RAID - 5)

# mkdir /mnt/raid5 (to create the RAID - 5 mount point)

# mount /dev/md0 /mnt/raid5 (to mount RAID - 5 on the mount point)

# mdadm -D /dev/md0 (to see the details of the RAID - 5 partition)

# mdadm /dev/md0 -f /dev/sdb (to failed the disk manually)

# mdadm /dev/md0 -r /dev/sdb (to remove the above failed disk)

# mdadm /dev/md0 -a /dev/sde (to add the new disk in place of failed disk)

# umount /mnt/raid5 (to unmount the raid file system)

# mdadm --stop /dev/md0 (to stop the RAID - 5 volume)

# mdadm /dev/md0 --add /dev/sdf (to add fourth disk to the RAID - 5 volume)

# mdadm --grow /dev/md0 --raid_device=4 (to grow the RAID - 5 file system)

35. What are the main advantages of RAID - 5

RAID - 5 uses Stripping with parity and requires only three disks. Because of Stripping the data reading and writing will be fast.And by usingparity we can recover the data if one of the three disks failed. So, the main advantage of RAID - 5 we can get fast writing, reading and also redundancy fault tolerance with less expensive.

36. How will you troubleshoot if one of the eight disks failed in LVM?

First umount the file system and add the new disk with same size of the failed disk to the volume group. Then move the data from failed physical volume to newly added physical volume and then remove the failed physical volume from the volume group. And finally mount the file system.

37. What is pvmove and when it is used in LVM?

The pvmove command is used to move the data from failed physical volume to newly added physical volume. This command is used when one of the physical volume is failed in the LVM.

38. How to inform the client and then troubleshoot if the disk is full?

First check which files are accessing more disk space by #du -h |sort - r command. if any temporary and junk files are present remove them from the disk to make a room for new or updated data. Then inform the actual situation to the client, take the permission from the client to get the lun from storage and extend the file system by adding that lun to the LVM.

39. Did you work on storage?

Actually I did not work on storage but I know the procedure how to export the lun from storage to client using iSCSI target. Then scan that lun at cleint side and add the lun to the LVM. I also know the storage hardware from Emc square, Netapp and others. And I am dreaming to work on storage, cloud and virtualization.

40. I have four disks each 1TB in RAID - (1+0). So, total how much disk space can I utilize in that RAID –

(1+0)? RAID - (1+0) means Mirroring + Stripping. It requires 4 disks, ie., 2 disks for mirroring and remaining 2 disks for stripping. And 5 - 10% disk space is used for superblock information. So, finally we can utilize 2TB - 2TB X 10% disk space in that RAID - (1+0).

41. If two disks failed in RAID - (1+0), can we recover the data?

The RAID - (1+0) requires minimum 4 disks and it uses Mirroring + Stripping. If one disk is failed we can

recover the data, but if two disks are failed we cannot recover the data.

42. How many types of disk space issues can we normally get?

(i) Disk is full.

(ii) Disk is failing or failed.

(iii) File system corrupted or crashed.

(iv) O/S is not recognizing the remote luns when scanning, ...etc.,

43. What is a link file and how many types?

Link file is a short cut file to the original file. Creating and removing (deleting) inks between two files is known as managing links. There are two types of links files available in Linux.

(i) Soft link

(ii) Hard link

44. What is soft link and how to create it?

Soft link is nothing but a short cut file. If original file is deleted, no use of short cut file. ie., we cannot access the original data by selecting the link file. Soft link can be applied on both directories and files. These files can be stored in any of the file system. ie., the original file may be in one file system and the link file may be on another file system. If we edit any file, the link files are also updated automatically. When we create a soft link file, the permissions are full permissions. The soft link file and the original file inode no's are different. The size of the soft link file is same as the length of the original file name. The soft link can be created by

# ln -s (to create a soft link)

# ln -s /root/script /root/Desktop/script (to create a link file for the script and stored on root Desktop)

45. What is hard link and how to create it?

Hard link in nothing but a backup file. If the original file is deleted, there is no effect on hard link file. i.e., we can access the original file data even though the link file is deleted. Hard links can be applied on files only not on directories. Hard link files can be stored in the same file system. ie., original and hard link files both should be in the same file system not on different file systems. The inode no's are same for original and hard link files. If the original is edited, the updations are applied on both original and hard link files. The size of the hard link file is same as the size of the original file.

46. What are the commands to search files and directories?

To search files and directories there are two commands.

(i) # locate

(ii) # find

47. Explain the locate command and how to use it?

locate always looks the locate database and not in a specific location. The data of the locate is stored in /var/lib/mlocate/mlocate.db file. If the data is not updated in locate database or the locate database is available or locate database is deleted, we cannot locate the files and directories. # updatedb is the command to update the locate database. locate database cannot be find the newly created files and directories. It is not recommended to use on production servers because it impacts on performance of the servers. So, to overcome this problem we normally use # find command on production servers.

# updatedb (to update the locate database)

# locate (to search the specified file or directory)

48. Explain the find command and how to use it?

find command required the specific location. Without specific location we cannot find the files or

directories.

# find (to find the specific file or directory)

The options are, -name -----> search files and directories

-prem -----> search for permissions

-size -----> search for sizes

-user -----> search for the owner

-uid -----> search for files/directories of uid)

-gid -----> search for files/directories of gid)

-group -----> search for group owner

-empty -----> search for empty files

-amin -----> search for access time

-mmin -----> " "

-cmin -----> " "

-atime -----> search for access day (access day, minutes, hrs, ...etc)

-mtime -----> search for modify day (change the content)

-ctime -----> search for change day (permissions, .....etc)

Examples :

# find / -name (to search for file names in / directory)

# find / -name -type f (to find file names only)

# find / -name -type d (to find directories with small letters only)

# find / -iname -t d (to search for small or capital letter files/directories)

#find / -empty (to search empty files or directories)

# find / -empty -type f (to search for empty files only)

# find / -empty -type d (to search for empty directories only)

# find / -name " *.mp3" (to search for .mp3 files only)

# find / -size 10M (to search for exact 10M size file/directories)

# find / -size -10M (to search for less than 10M size files/directories)

# find / -size +10M (to search for greater than 10M size files/directories)

# find / -user student (to search for student user files/directories)

# find / -group student (to search for student group files/directories)

# find / -user student -not -group student (to search for student user files and not student

group files)

# find / -user student -o -group student (to search for student user and student group

files/directories)

# find / -uid (to search for files/directories which belongs to the user having the specified user id)

# find / -gid (to search for files/directories which belongs to the group having the specified group id)

# find / -prem 755 (to search file/directories which are having the

permissions 755)

# find / -prem -755 (to search file/directories which are having the

permissions below 755 and also at least one match also)

# find / -mmin 20 (to search for files/directories which are modified within 20 minutes, +20 ----> above 20 minutes and -20 -----> below 20 minutes)

# find / -mtime 2 (to search files/directories which are modified within 2 days)

# find / -name "*.mp3" -exec rm -rf { } \; (to search all .mp3 files and delete them)

# find / -name "*.mp3" -exec cp -a { } /ram \ ;(to search all mp3 files and copy them into /ram

directory)

# find / -user student -exec cp -a { } /ram \; (to search student user's files and directories and copy them into /ram directory)

# find / -nouser -exec mv -a { } /home/ram \; (to search files/directories which are not

belongs to any user and move them into /home/ram directory)

# du -h / |sort -r |head -n 10 (to search 10 big size files in reverse order)

Linux, CCNA and MCSE Questions

Monday, October 17, 2016

Logical Volume Management and RAID Levels

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Linux, CCNA and MCSE Questions: User Managment