RAID configuration experiment

Catalog

One 、RAID  Disk array Introduction

Two 、 Commonly used RAID Array Introduction

1、RAID0 Disk array Introduction

2、RAID 1 Disk array Introduction

3、RAID 5 Disk array Introduction

4、RAID 10 Disk array Introduction

3、 ... and 、RAID Array experiment

         1、RAID 0 disk array

         2、RAID 1 disk array

         3、RAID 5 disk array

         4、RAID 10 disk array  

summary ：

---

One 、RAID  Disk array Introduction

RAID： Independent redundant disk array

working principle ： Combine multiple independent physical hard disks in different ways to form a hard disk group ( Logical hard disk ), So as to provide higher storage performance than a single hard disk and provide data backup technology

RAID Commonly used ：RAID0,RAID1,RAID5,RAID6,RAID1+0,RAID 0+1 etc.

Two 、 Commonly used RAID Array Introduction

1、RAID0 Disk array Introduction

working process ： Put multiple physical hard disk devices ( At least two ） Connected in series by hardware or software , Form a large volume group , And write the data to each physical hard disk in turn , It is a kind of striped storage .

analysis ：RAID 0 It has a high data transmission rate ; There is no redundant （ Backup ）、 check , The reliability guarantee of data is low , It cannot be used in occasions with high safety requirements .

2、RAID 1 Disk array Introduction

working process ： Put multiple physical hard disk devices ( At least two ） Connected in series by hardware or software , Form a large volume group , The contents of each disk are the same , It is a kind of mirrored storage .

analysis ： Disk data mirroring realizes data redundancy （ Backup ）, When raw data is busy , Data can be read directly from the mirror copy , therefore RAID 1 Can improve read performance , But the reading performance is not RAID 0 high . High data security and reliability . When a disk fails , The system can automatically switch to read and write on the mirror disk .

3、RAID 5 Disk array Introduction

working principle ： Save data parity information to other hard disk devices .RAID 5 The parity information of the data in the disk array is not stored separately in a — Block hard disk device , Instead, it is stored on other hard disk devices besides itself .

analysis ： from N( At least 3 Block hard disk ) The disks form an array , A data generation N-1 A strip , As well as 1 Check data , common N The data is in N Cycle balanced storage on the block disk ;N Read and write at the same time , High reading performance , But because of the problem of checking mechanism , Write performance is relatively low (N-1)/N Disk utilization ; High reliability , Allow bad 1 Block plate , It doesn't affect all the data

4、RAID 10 Disk array Introduction

working principle ：RAID 10 The technology is RAID1+RAID0 One of the technologies “ assembly ”. You need at least 4 Block hard disk to build , Two of them are made into RAID 1 disk array , To ensure data security ; And then two more RAID1 Raid implementation   RAID 0 technology , Into the — Step 1: improve the reading and writing speed of hard disk devices .

analysis ： RAID1+0  array ： First make a mirror image , And then make a strip ,N Block plate (N For the even , At least 4 A hard disk ) After two mirror images , Then combine it into a RAID 0, High performance , High reliability .

Four kinds of RAID Array comparison ：

RAID Level	Number of hard disks	Disk utilization	Check function	Can break several disks	Write performance
RAID0	N individual	N	nothing	0	Of a single hard disk N times
RAID1	N individual （ even numbers ）	N/2	nothing	1	Need to write two hard disks , Prepare for each other
RAID5	least 3 individual	(N-1)/N	Yes	1	Need to calculate and verify
RAID10	least 4 individual	N/2	nothing	At most, each group can only be broken 1 individual	Double write calculation verification is required

3、 ... and 、RAID Array experiment

RAID Use command   mdadm

mdadm function ： Used to manage RAID Raid group , You can create 、 adjustment 、 monitor 、 Delete and other complete management operations

Grammar format ：mdadm [ Options ] Device name

Options ：-D ---- Show RAID Device details

           -G ---- change RAID Size or shape of equipment

           -C ---- hold RAID Information is written into each member super block

           -v ----- Show RAID Details of the creation process

           -l ----- Appoint RAID The level of

           -n ---- Appoint RAID Number of active devices in

           -f ---- hold RAID Members are listed as having problems , To remove the member

           -r ---- hold RAID Members move out RAID equipment

           -a ---- towards RAID Add — Members

           -x ----- Specify initial RAID Number of spare members of the device

newly added 4 A hard disk , Set one for each hard disk 2G Main partition

Turn off firewall and central protection

1、RAID 0 disk array

( hold sdb1 and sdc1 Form a RAID 0 Array of disks )

① Grammatical format analysis ：mdadm -Cv /dev/md0 -n2 -l0 /dev/sd[b,c]1

mdadm： command , At this point, create a disk array

-Cv Can be written separately -C -v  ： Means to create a disk card , And show the detailed process

/dev/md0   ： Name of the array created

-n2 ： Appoint RAID The number of active devices in is 2

-10 ： Appoint RAID The number of levels is 0

/dev/sd[b,c]1    Which disks make up the disk array

② see mdadm -D /dev/md0 

③ format

④ mount

 

It can also be permanently attached ：

 mount -a    

Speed measurement test ：

 2、RAID 1 disk array

①  hold sdd1 and sde1 Form a RAID 0 Array of disks

②   see   mdadm -D /dev/md1

 ③ format

 ④ mount Or permanently mount    vim /etc/fstab

3、RAID 5 disk array  

Use sdb2、sdc2、sdd2 form raid 5 And sde1 As a backup

① 

②

 ③ format

④ Mount or permanently mount    vim /etc/fstab

NAME      MAJ:MIN RM  SIZE RO TYPE   MOUNTPOINT
sda         8:0    0  100G  0 disk   
├─sda1      8:1    0  500M  0 part   /boot
├─sda2      8:2    0  7.8G  0 part   [SWAP]
└─sda3      8:3    0 91.7G  0 part   /
sdb         8:16   0   20G  0 disk   
├─sdb1      8:17   0    4G  0 part   
│ └─md127   9:127  0    8G  0 raid0  /data/raid0
├─sdb2      8:18   0    2G  0 part   
│ └─md5     9:5    0    4G  0 raid5  /data/raid5
├─sdb3      8:19   0    2G  0 part   
├─sdb4      8:20   0    1K  0 part   
└─sdb5      8:21   0   12G  0 part   
  └─md10    9:10   0   22G  0 raid10 /data/raid10
sdc         8:32   0   20G  0 disk   
├─sdc1      8:33   0    4G  0 part   
│ └─md127   9:127  0    8G  0 raid0  /data/raid0
├─sdc2      8:34   0    2G  0 part   
│ └─md5     9:5    0    4G  0 raid5  /data/raid5
├─sdc3      8:35   0    2G  0 part   
├─sdc4      8:36   0    1K  0 part   
└─sdc5      8:37   0   12G  0 part   
  └─md10    9:10   0   22G  0 raid10 /data/raid10
sdd         8:48   0   20G  0 disk   
├─sdd1      8:49   0    4G  0 part   
│ └─md126   9:126  0    4G  0 raid1  /data/raid1
├─sdd2      8:50   0    2G  0 part   
│ └─md5     9:5    0    4G  0 raid5  /data/raid5
├─sdd3      8:51   0    3G  0 part   
├─sdd4      8:52   0    1K  0 part   
└─sdd5      8:53   0   11G  0 part   
  └─md10    9:10   0   22G  0 raid10 /data/raid10
sde         8:64   0   20G  0 disk   
├─sde1      8:65   0    4G  0 part   
│ └─md126   9:126  0    4G  0 raid1  /data/raid1
├─sde2      8:66   0    2G  0 part   
├─sde3      8:67   0    2G  0 part   
│ └─md5     9:5    0    4G  0 raid5  /data/raid5
├─sde4      8:68   0    1K  0 part   
└─sde5      8:69   0   12G  0 part   
  └─md10    9:10   0   22G  0 raid10 /data/raid10
sr0        11:0    1  4.3G  0 rom  

Simulate this sdb2 The dish is broken

Before bad ：

  Set fault ： Set up sdb2 Something goes wrong

  see raid 5

4、RAID 10 disk array  

①

②

 ③ format

④ Mount or permanently mount    vim /etc/fstab

 

 ⑤  [[email protected] data]# lsblk 
NAME      MAJ:MIN RM  SIZE RO TYPE   MOUNTPOINT
sda         8:0    0  100G  0 disk   
├─sda1      8:1    0  500M  0 part   /boot
├─sda2      8:2    0  7.8G  0 part   [SWAP]
└─sda3      8:3    0 91.7G  0 part   /
sdb         8:16   0   20G  0 disk   
├─sdb1      8:17   0    4G  0 part   
│ └─md127   9:127  0    8G  0 raid0  /data/raid0
├─sdb2      8:18   0    2G  0 part   
│ └─md5     9:5    0    4G  0 raid5  /data/raid5
├─sdb3      8:19   0    2G  0 part   
├─sdb4      8:20   0    1K  0 part   
└─sdb5      8:21   0   12G  0 part   
  └─md10    9:10   0   22G  0 raid10 /data/raid10
sdc         8:32   0   20G  0 disk   
├─sdc1      8:33   0    4G  0 part   
│ └─md127   9:127  0    8G  0 raid0  /data/raid0
├─sdc2      8:34   0    2G  0 part   
│ └─md5     9:5    0    4G  0 raid5  /data/raid5
├─sdc3      8:35   0    2G  0 part   
├─sdc4      8:36   0    1K  0 part   
└─sdc5      8:37   0   12G  0 part   
  └─md10    9:10   0   22G  0 raid10 /data/raid10
sdd         8:48   0   20G  0 disk   
├─sdd1      8:49   0    4G  0 part   
│ └─md126   9:126  0    4G  0 raid1  /data/raid1
├─sdd2      8:50   0    2G  0 part   
│ └─md5     9:5    0    4G  0 raid5  /data/raid5
├─sdd3      8:51   0    3G  0 part   
├─sdd4      8:52   0    1K  0 part   
└─sdd5      8:53   0   11G  0 part   
  └─md10    9:10   0   22G  0 raid10 /data/raid10
sde         8:64   0   20G  0 disk   
├─sde1      8:65   0    4G  0 part   
│ └─md126   9:126  0    4G  0 raid1  /data/raid1
├─sde2      8:66   0    2G  0 part   
├─sde3      8:67   0    2G  0 part   
│ └─md5     9:5    0    4G  0 raid5  /data/raid5
├─sde4      8:68   0    1K  0 part   
└─sde5      8:69   0   12G  0 part   
  └─md10    9:10   0   22G  0 raid10 /data/raid10
sr0        11:0    1  4.3G  0 rom    

summary ：

RAID 0 It is a strip type   Don't break any disk , Read write speed block , No backup

RAID 1 It is an image type   Can break a disk , The reading and writing speed is not RAID 0 block , But there are backups , High safety

RAID 5 It is a strip plus check type , The most widely used type in production . The worst one is allowed

RAID 10 It's the mirror image first and the strip , Each group raid 1 A bad one is allowed at most