Linux创建RAID5_实战

Linux创建RAID5实战

Linux创建RAID5

1. RAID5最少由三个硬盘组成，它将数据分散存储于阵列中的每个硬盘，并且还伴有一个数据校验位，数据位与校验位通过算法能相互验证
2. RAID5最多能允许一个硬盘损坏，有容错性
3. RAID5相对于其它的组合方式，在容错与成本方面有一个平衡，一般的磁盘阵列，最常使用的就是RAID5这种方式
   
   

创建RAID5，并格式化，挂载使用

1. 添加4块虚拟硬盘，并全部分区，分区ID为fd

[root@localhost ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 10G 0 disk
sdb 8:16 0 10G 0 disk
sdc 8:32 0 10G 0 disk
sdd 8:48 0 10G 0 disk
sr0 11:0 1 7.3G 0 rom
nvme0n1 259:0 0 80G 0 disk
├─nvme0n1p1 259:1 0 1G 0 part /boot
└─nvme0n1p2 259:2 0 79G 0 part
├─rhel-root 253:0 0 50G 0 lvm /
├─rhel-swap 253:1 0 2G 0 lvm [SWAP]
└─rhel-home 253:2 0 27G 0 lvm /home


• 查看已经分区的四块硬盘

[root@localhost ~]# fdisk -l | grep raid
/dev/sda1 2048 20971519 20969472 10G fd Linux raid autodetect
/dev/sdc1 2048 20971519 20969472 10G fd Linux raid autodetect
/dev/sdb1 2048 20971519 20969472 10G fd Linux raid autodetect
/dev/sdd1 2048 20971519 20969472 10G fd Linux raid autodetect


1. 创建RAID5，并添加1个热备份盘

[root@localhost ~]# mdadm -C -v /dev/md5 -l5 -n3 /dev/sd{a,b,c}1 -x1 /dev/sdd
mdadm: layout defaults to left-symmetric
mdadm: layout defaults to left-symmetric
mdadm: chunk size defaults to 512K
mdadm: partition table exists on /dev/sdd
mdadm: partition table exists on /dev/sdd but will be lost or
meaningless after creating array
mdadm: size set to 10475520K
Continue creating array? y
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md5 started.


1. 查看 raidstat 状态

[root@localhost ~]# cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4]
md5 : active raid5 sdc1[4] sdd[3](S) sdb1[1] sda1[0]
20951040 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/2] [UU_]
[==================>..] recovery = 91.0% (9533852/10475520) finish=0.0min speed=202150K/secunused devices: <none>
//再次查看
[root@localhost ~]# cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4]
md5 : active raid5 sdc1[4] sdd[3](S) sdb1[1] sda1[0]
20951040 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/3] [UUU]unused devices: <none>


1. 查看 RAID5 的详细信息

[root@localhost ~]# mdadm -D /dev/md5
/dev/md5:
Version : 1.2
Creation Time : Wed Dec 16 14:08:53 2020
Raid Level : raid5
Array Size : 20951040 (19.98 GiB 21.45 GB)
Used Dev Size : 10475520 (9.99 GiB 10.73 GB)
Raid Devices : 3
Total Devices : 4
Persistence : Superblock is persistent Update Time : Wed Dec 16 14:09:46 2020
State : clean
Active Devices : 3
Working Devices : 4
Failed Devices : 0
Spare Devices : 1 Layout : left-symmetric
Chunk Size : 512KConsistency Policy : resync Name : localhost:5 (local to host localhost)
UUID : 4b8e1fdf:7389efbb:77633231:48a89857
Events : 18 Number Major Minor RaidDevice State
0 8 1 0 active sync /dev/sda1
1 8 17 1 active sync /dev/sdb1
4 8 33 2 active sync /dev/sdc1 3 8 48 - spare /dev/sdd


1. 格式化 /dev/md5 ,格式化类型为xfs

[root@localhost ~]# mkfs.xfs /dev/md5
meta-data=/dev/md5 isize=512 agcount=16, agsize=327296 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=0
= reflink=1
data = bsize=4096 blocks=5236736, imaxpct=25
= sunit=128 swidth=256 blks
naming =version 2 bsize=4096 ascii-ci=0, ftype=1
log =internal log bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
[root@localhost ~]# blkid /dev/md5
/dev/md5: UUID="d1a0805f-5685-4af8-9935-9abb1dae7636" TYPE="xfs"


1. 挂载 /dev/md5 ，挂载点为 /radi5

[root@localhost ~]# mkdir /raid5
[root@localhost ~]# mount /dev/md5 /raid5
[root@localhost ~]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 887M 0 887M 0% /dev
tmpfs 904M 0 904M 0% /dev/shm
tmpfs 904M 8.7M 895M 1% /run
tmpfs 904M 0 904M 0% /sys/fs/cgroup
/dev/mapper/rhel-root 50G 4.5G 46G 9% /
/dev/mapper/rhel-home 27G 225M 27G 1% /home
/dev/nvme0n1p1 1014M 173M 842M 18% /boot
tmpfs 181M 0 181M 0% /run/user/0
/dev/md5 20G 176M 20G 1% /raid5