What is raid 1 ? and how to configure in redhat linux server 1
hello guys today we will discuss about RAID 1. RAID 1 is a storage management method .Here we will learn how to implement in redhat linux .RAID 1 is aslo call disk mirroring because this method in used two or more heard drive every heard drive in data copy data same size so call mirroring .RAID 1 is provide full data redundancy .this method is provide very best data back up system .here we learn RAID 1 in redhat linux server .here i used partition if u want u can also real machine.
note if u used in real machine so just follow instruction
1{ #fdisk /dev/sda is used virtual box and real machine if u install or connect external other heard driver so u need #fdisk /dev/sdb its used for external 1 heard disk if u add another add so u used #fdisk /dev/sdc like this we add heard drive so used #fdisk /dev/sdb ,#fdisk /dev/sdc #fdisk /dev/sdd ,#fdisk /dev/sde }
now we start with partition
[root@localhost ~]# fdisk /dev/sda The number of cylinders for this disk is set to 4177. 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): p Disk /dev/sda: 34.3 GB, 34359738368 bytes 255 heads, 63 sectors/track, 4177 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 * 1 3315 26627706 83 Linux /dev/sda2 3316 3697 3068415 82 Linux swap / Solaris /dev/sda4 3698 4177 3855600 5 Extended 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) Command (m for help): n Command action l logical (5 or over) p primary partition (1-4) l First cylinder (3698-4177, default 3698): Using default value 3698 Last cylinder or +size or +sizeM or +sizeK (3698-4177, default 4177): +200M Command (m for help): n Command action l logical (5 or over) p primary partition (1-4) l First cylinder (3723-4177, default 3723): Using default value 3723 Last cylinder or +size or +sizeM or +sizeK (3723-4177, default 4177): +200M Command (m for help): p Disk /dev/sda: 34.3 GB, 34359738368 bytes 255 heads, 63 sectors/track, 4177 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 * 1 3315 26627706 83 Linux /dev/sda2 3316 3697 3068415 82 Linux swap / Solaris /dev/sda4 3698 4177 3855600 5 Extended /dev/sda5 3698 3722 200781 83 Linux /dev/sda6 3723 3747 200781 83 Linux Command (m for help): t Partition number (1-6): 6 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 6 to fd (Linux raid autodetect) Command (m for help): p^H^H Disk /dev/sda: 34.3 GB, 34359738368 bytes 255 heads, 63 sectors/track, 4177 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 * 1 3315 26627706 83 Linux /dev/sda2 3316 3697 3068415 82 Linux swap / Solaris /dev/sda4 3698 4177 3855600 5 Extended /dev/sda5 3698 3722 200781 83 Linux /dev/sda6 3723 3747 200781 fd Linux raid autodetect Command (m for help): t Partition number (1-6): 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. [root@localhost ~]# partprobe /dev/sda
After creating partition we will going to create Raid1
[root@localhost ~]#mdadm – -create /dev/md1 – -level=0 – -raid-devices=2 /dev/sda5 /dev/sda6
now u can check your raid1 through # cat /proc/mdstat
[root@localhost ~]# mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sda5 /dev/sda6
mdadm: array /dev/md0 started.
[root@localhost ~]# cat /proc/mdstate
cat: /proc/mdstate: No such file or directory
[root@localhost ~]# cat /proc/mdstat
Personalities : [raid1]
md0 : active raid0 sda6[1] sda5[1t]
594176 blocks 64k chunks
unused devices: <none>
[root@localhost ~]#Thank you
by vishnu sharma
