RAID01 . HOW TO CONFIGURE RAID 01 IN LINUX.

RAID O1 has the benefits of RAID 0 speed and RAID 1 safety .It is also called as mirror of stripes. Raid1 increase read speed and reduce access time is the main advantage. The second one is data safety.


Raid0 also know as disk stripping,it is basically a technique that breaks up a file and spreads the data across all the disk drives in a raid system.
Drawback to Raid 0 is that there is no redundancy(no parity), that means if one drive fails your all data would be lost

raid01 in linux

Let the data be 1 , 2, 3, 4 ,as you can see the diagram . First its raid 1 (consists of two partition ) made upon two raid which is raid 0 . And raid 1  which is best for data mirroring .So its sending 1,2,3,4 data equally to both partition (raid 0) .  Raid 1(/dev/md0) size will be 2000 mb , but you might be thinking its partition total size (/dev/md1 and /dev/md0) is 4000 mb so how it can be 2000 mb ? Because it equally distributes data to both partition so it can take data from any partition , if one crashes . Then comes raid 0 which also requires 2 harddisk but it doesn’t equally distributes data , raid 0 spreads the data to both  disk  . In diagram , it keeping 1 & 3 data in sda5 disk and 2 & 4 in sda6 . Same happens in /dev/md2 .

Conclusion :Raid 1 (/dev/md0)takes data either from /dev/md1(raid 0)  or  /dev/md2(raid 0) . In raid01, the loss of any drive (one in each group) in a set cause the failure of that entire set and the set is removed from the raid system.
(In the two set case) Generally this means you are left with a raid0 systems made up of the remaining set of drives.

HOW TO CONFIGURE RAID01 IN LINUX

  • First check how many partition you have in your system by fdisk -l command .
[root@localhost ~]# fdisk -l

Disk /dev/sda: 537.9 GB, 537932857344 bytes
255 heads, 63 sectors/track, 65399 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1       50993   409601241   83  Linux
/dev/sda2           50994       57367    51199155   82  Linux swap / Solaris
/dev/sda4           57368       65399    64517040    5  Extended

partition in linux

  • Now we will create four partitions . (raid 01 requires four disks )
[root@localhost ~]# fdisk /dev/sda

The number of cylinders for this disk is set to 65399.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)
Command (m for help): m
Command action
   a   toggle a bootable flag
   b   edit bsd disklabel
   c   toggle the dos compatibility flag
   d   delete a partition
   l   list known partition types
   m   print this menu
   n   add a new partition
   o   create a new empty DOS partition table
   p   print the partition table
   q   quit without saving changes
   s   create a new empty Sun disklabel
   t   change a partition's system id
   u   change display/entry units
   v   verify the partition table
   w   write table to disk and exit
   x   extra functionality (experts only)
  • As shown above command n is for adding a new partition. Create four partition but make sure all four are of same size .
Command (m for help): n
Command action
   l   logical (5 or over)
   p   primary partition (1-4)
l
First cylinder (57368-65399, default 57368):
Using default value 57368
Last cylinder or +size or +sizeM or +sizeK (57368-65399, default 65399): +1000M

Command (m for help): n
Command action
   l   logical (5 or over)
   p   primary partition (1-4)
l
First cylinder (57491-65399, default 57491):
Using default value 57491
Last cylinder or +size or +sizeM or +sizeK (57491-65399, default 65399): +1000M

Command (m for help): n
Command action
   l   logical (5 or over)
   p   primary partition (1-4)
l
First cylinder (57614-65399, default 57614):
Using default value 57614
Last cylinder or +size or +sizeM or +sizeK (57614-65399, default 65399): +1000M

Command (m for help): n
Command action
   l   logical (5 or over)
   p   primary partition (1-4)
l
First cylinder (57737-65399, default 57737):
Using default value 57737
Last cylinder or +size or +sizeM or +sizeK (57737-65399, default 65399): +1000M

Command (m for help): p
Disk /dev/sda: 537.9 GB, 537932857344 bytes
255 heads, 63 sectors/track, 65399 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1       50993   409601241   83  Linux
/dev/sda2           50994       57367    51199155   82  Linux swap / Solaris
/dev/sda4           57368       65399    64517040    5  Extended
/dev/sda5           57368       57490      987966   83  Linux
/dev/sda6           57491       57613      987966   83  Linux
/dev/sda7           57614       57736      987966   83  Linux
/dev/sda8           57737       57859      987966   83  Linux

Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table.
The new table will be used at the next reboot.
Syncing disks.

creating partition in linux

  • After creating partition we have to change partition type to raid . Follow below commands .
  • In last don’t forget to type partprobe command to save changes made .
[root@localhost ~]# fdisk /dev/sda

The number of cylinders for this disk is set to 65399.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)

Command (m for help): t
Partition number (1-8): 8
Hex code (type L to list codes): l
 0  Empty           1e  Hidden W95 FAT1 80  Old Minix       bf  Solaris
 1  FAT12           24  NEC DOS         81  Minix / old Lin c1  DRDOS/sec (FAT-
 2  XENIX root      39  Plan 9          82  Linux swap / So c4  DRDOS/sec (FAT-
 3  XENIX usr       3c  PartitionMagic  83  Linux           c6  DRDOS/sec (FAT-
 4  FAT16 <32M      40  Venix 80286     84  OS/2 hidden C:  c7  Syrinx
 5  Extended        41  PPC PReP Boot   85  Linux extended  da  Non-FS data
 6  FAT16           42  SFS             86  NTFS volume set db  CP/M / CTOS / .
 7  HPFS/NTFS       4d  QNX4.x          87  NTFS volume set de  Dell Utility
 8  AIX             4e  QNX4.x 2nd part 88  Linux plaintext df  BootIt
 9  AIX bootable    4f  QNX4.x 3rd part 8e  Linux LVM       e1  DOS access
 a  OS/2 Boot Manag 50  OnTrack DM      93  Amoeba          e3  DOS R/O
 b  W95 FAT32       51  OnTrack DM6 Aux 94  Amoeba BBT      e4  SpeedStor
 c  W95 FAT32 (LBA) 52  CP/M            9f  BSD/OS          eb  BeOS fs
 e  W95 FAT16 (LBA) 53  OnTrack DM6 Aux a0  IBM Thinkpad hi ee  EFI GPT
 f  W95 Ext'd (LBA) 54  OnTrackDM6      a5  FreeBSD         ef  EFI (FAT-12/16/
10  OPUS            55  EZ-Drive        a6  OpenBSD         f0  Linux/PA-RISC b
11  Hidden FAT12    56  Golden Bow      a7  NeXTSTEP        f1  SpeedStor
12  Compaq diagnost 5c  Priam Edisk     a8  Darwin UFS      f4  SpeedStor
14  Hidden FAT16 <3 61  SpeedStor       a9  NetBSD          f2  DOS secondary
16  Hidden FAT16    63  GNU HURD or Sys ab  Darwin boot     fb  VMware VMFS
17  Hidden HPFS/NTF 64  Novell Netware  b7  BSDI fs         fc  VMware VMKCORE
18  AST SmartSleep  65  Novell Netware  b8  BSDI swap       fd  Linux raid auto
1b  Hidden W95 FAT3 70  DiskSecure Mult bb  Boot Wizard hid fe  LANstep
1c  Hidden W95 FAT3 75  PC/IX           be  Solaris boot    ff  BBT

Hex code (type L to list codes): fd
Changed system type of partition 8 to fd (Linux raid autodetect)

Command (m for help): t
Partition number (1-8): 7
Hex code (type L to list codes): fd
Changed system type of partition 7 to fd (Linux raid autodetect)

Command (m for help): t
Partition number (1-8): 6
Hex code (type L to list codes): fd
Changed system type of partition 6 to fd (Linux raid autodetect)

Command (m for help): t
Partition number (1-8): 5
Hex code (type L to list codes): fd
Changed system type of partition 5 to fd (Linux raid autodetect)

Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table.
The new table will be used at the next reboot.
Syncing disks.

changing partition type in linux

  • Now check with fdisk -l command that partition type is been changed or not .
  • You will find your partition type is raid . So your partition is ready for raid configuration .
[root@localhost ~]# fdisk -l
Disk /dev/sda: 537.9 GB, 537932857344 bytes
255 heads, 63 sectors/track, 65399 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1       50993   409601241   83  Linux
/dev/sda2           50994       57367    51199155   82  Linux swap / Solaris
/dev/sda4           57368       65399    64517040    5  Extended
/dev/sda5           57368       57490      987966   fd  Linux raid autodetect
/dev/sda6           57491       57613      987966   fd  Linux raid autodetect
/dev/sda7           57614       57736      987966   fd  Linux raid autodetect
/dev/sda8           57737       57859      987966   fd  Linux raid autodetect

raid partition in linux

  • As shown in diagram first we will create Raid 0 (/dev/md1) including sda5 and sda6
  • In this command level will be 0 because we are creating raid0
  • After create type what raid you wanna create .
  • And in raid devices give partition name .
  • Like i’m creating /dev/md1 which will be raid 0 (level=0 ) of raid devices /devsda5 and /devsda6 .
[root@localhost ~]# mdadm --create /dev/md1 --level=0 --raid-devices=2 /dev/sda5 /dev/sda6
mdadm: array /dev/md1 started.
  • Then create /dev/md2 (raid 0) including sda7 and sda8
[root@localhost ~]# mdadm --create /dev/md2 --level=0 --raid-devices=2 /dev/sda7 /dev/sda8
mdadm: array /dev/md2 started.
  • Now we will take both /dev/md1 & /dev/md2  , and make /dev/md0 (raid 1)
  • In this command level will be 1 because we are creating raid 1.
[root@localhost ~]# mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/md1 /dev/md2
mdadm: array /dev/md0 started.

raid in linux

  • Check by cat /proc/mdstat command whether your raid is been created or not .
  • It will also show which partition is been used in that raid (md)
[root@localhost ~]# cat /proc/mdstat

Personalities : [raid0] [raid1]
md2 : active raid0 sda8[1] sda7[0]
      1975680 blocks 64k chunks
md1 : active raid0 sda6[1] sda5[0]
      1975680 blocks 64k chunks
md0 : active raid1 md2[1] md1[0]
      1975616 blocks [2/2] [UU]
unused devices: <none>

raid in linux

  • Our raid 01 is ready but we have to mount it to somewhere for saving data .But before mounting format /dev/md0 .
[root@localhost ~]# mkfs.ext3 /dev/md0

mke2fs 1.39 (29-May-2006)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
247296 inodes, 493904 blocks
24695 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=507510784
16 block groups
32768 blocks per group, 32768 fragments per group
15456 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912
Writing inode tables: done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 32 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.

format in linux

  • Create a folder . My folder name is Deepit .
[root@localhost ~]# mkdir Deepit
  • Now mount /dev/md0 to that folder .
[root@localhost ~]# mount /dev/md0 Deepit
  • To check type df  -h
[root@localhost ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1             379G  2.0G  357G   1% /
tmpfs                 947M     0  947M   0% /dev/shm
/dev/md0              1.9G   35M  1.8G   2% /root/Deepit

mount in linux

  • For permanent mounting Open  /etc/fstab file .
[root@localhost ~]# vim /etc/fstab
  • Now make entry as shown below .
  • First which raid your mounting
  • second where to mount
  • third file type  and rest will be same  .
LABEL=/                 /                       ext3    defaults        1 1
tmpfs                   /dev/shm                tmpfs   defaults        0 0
devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
sysfs                   /sys                    sysfs   defaults        0 0
proc                    /proc                   proc    defaults        0 0
LABEL=SWAP-sda2         swap                    swap    defaults        0 0
/dev/md0                /root/Deepit            ext3    defaults        0 0
~
~
~
~
~
~

mounting in linux

  • Press ESC key and type :wq( to save and quit.
~
~
~
~
~
:wq

Your RAID 01 is ready .

 

STEPS TO DELETE RAID01

  • First go to /vim/fstab .
[root@localhost ~]# vim /etc/fstab
  • And add # in front that  entry it will comment out(unread) that entry .
#/dev/md0                /root/Deepit            ext3    defaults        0 0

unmounting in linux

  • Check by df -h command where its mounted
[root@localhost ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1             379G  2.0G  357G   1% /
tmpfs                 947M     0  947M   0% /dev/shm
/dev/md0              1.9G   35M  1.8G   2% /root/Deepit
  • To unmount type Umount and folder name where its mounted .
  • Then again check .
[root@localhost ~]# umount Deepit
[root@localhost ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1             379G  2.0G  357G   1% /
tmpfs                 947M     0  947M   0% /dev/shm

unmounting in linux

  • Now we will remove raid created by us .
  • First stop raid by   madadm   — stop    raidname
  • Then remove it       mdadm   — remove    raidname
[root@localhost ~]# mdadm --stop /dev/md0
mdadm: stopped /dev/md0
[root@localhost ~]# mdadm --remove /dev/md0
[root@localhost ~]# mdadm --stop /dev/md1
mdadm: stopped /dev/md1
[root@localhost ~]# mdadm --remove /dev/md1
[root@localhost ~]# mdadm --stop /dev/md2
mdadm: stopped /dev/md2
[root@localhost ~]# mdadm --remove /dev/md2

removing raid in linux

  • Check by cat /proc/mdstat command .
[root@localhost ~]# cat /proc/mdstat
Personalities : [raid0] [raid1]
unused devices: <none>
  • Now remove raid type partition .
  • command d is for deleting partition .
[root@localhost ~]# fdisk /dev/sda

The number of cylinders for this disk is set to 65399.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)

Command (m for help): d
Partition number (1-8): 8

Command (m for help): d
Partition number (1-7): 7

Command (m for help): d
Partition number (1-6): 6

Command (m for help): d
Partition number (1-5): 5

Command (m for help): p
Disk /dev/sda: 537.9 GB, 537932857344 bytes
255 heads, 63 sectors/track, 65399 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1       50993   409601241   83  Linux
/dev/sda2           50994       57367    51199155   82  Linux swap / Solaris
/dev/sda4           57368       65399    64517040    5  Extended

Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table.
The new table will be used at the next reboot.
Syncing disks.

removing partition in linux

  • Run partprobe command to save changes  made .
[root@localhost ~]# partprobe /dev/sda
  • Check by fdisk  -l command your partition is removed or not .
[root@localhost ~]# fdisk -l

Disk /dev/sda: 537.9 GB, 537932857344 bytes
255 heads, 63 sectors/track, 65399 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1       50993   409601241   83  Linux
/dev/sda2           50994       57367    51199155   82  Linux swap / Solaris
/dev/sda4           57368       65399    64517040    5  Extended

 

WONDERING HOW TO INSTALL LINUX 5 . CHECK IT OUT

WHAT IS PYTHON SERVER AND HOW TO CONFIGURE PYTHON AS WEB SERVER IN LINUX.

HOW TO COMBINE FILES IN A SINGLE FILE AND HOW TO COMPRESS FILE IN LINUX

 

 

 

 

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s