【linux】mdadm-raid1管理
作者:互联网
文章目录
回顾:
raid1原理:
RAID-1 :mirroring(镜像卷)需要磁盘两块以上
原理:是把一个磁盘的数据镜像到另一个磁盘上,也就是说数据在写入一块磁盘的同时,会在另一块闲置的磁盘上生成镜像文件,(同步)
特性:当一块硬盘失效时,系统会忽略该硬盘,转而使用剩余的镜像盘读写数据,具备很好的磁盘冗余能力。
磁盘利用率为50%,即2块100G的磁盘构成RAID1只能提供100G的可用空间。
实验内容:
- 创建raid1
- 添加一个G的热备盘
- 模拟磁盘故障,自动顶替故障
- 卸载阵列
1)创建分区
fdisk /dev/sdd[root@centos7-xinsz08 ~]# ll /dev/sdd*brw-rw----. 1 root disk 8, 48 2月 27 16:22 /dev/sdd brw-rw----. 1 root disk 8, 49 2月 27 16:22 /dev/sdd1 brw-rw----. 1 root disk 8, 50 2月 27 16:22 /dev/sdd2 brw-rw----. 1 root disk 8, 51 2月 27 16:22 /dev/sdd3 brw-rw----. 1 root disk 8, 52 2月 27 16:22 /dev/sdd4 `
2)创建raid1
[root@centos7-xinsz08 ~]# mdadm -C -v /dev/md2 -l 1 -n 2 -x 1 /dev/sdd1 /dev/sdd[2,3]mdadm: Note: this array has metadata at the start and may not be suitable as a boot device. If you plan to store '/boot' on this device please ensure that your boot-loader understands md/v1.x metadata, or use --metadata=0.90 mdadm: size set to 3140608K mdadm: largest drive (/dev/sdd1) exceeds size (3140608K) by more than 1% Continue creating array? y mdadm: Defaulting to version 1.2 metadata mdadm: array /dev/md2 started.
3) 将RAID1信息保存到配置文件中
[root@centos7-xinsz08 ~]# mdadm -Dsv > /etc/mdadm.conf
4)检查我们的磁盘阵列
[root@centos7-xinsz08 ~]# mdadm -D /dev/md2/dev/md2: //设备名 Version : 1.2 Creation Time : Thu Feb 27 16:24:39 2020 .//创建时间 Raid Level : raid1 Array Size : 3140608 (3.00 GiB 3.22 GB) Used Dev Size : 3140608 (3.00 GiB 3.22 GB) Raid Devices : 2 Total Devices : 3 Persistence : Superblock is persistent Update Time : Thu Feb 27 16:25:01 2020 State : clean Active Devices : 2 //当前活动设备 Working Devices : 3 .//工作设备 Failed Devices : 0 // 失效设备 Spare Devices : 1 //热备盘的数量 Consistency Policy : resync Name : centos7-xinsz08:2 (local to host centos7-xinsz08) UUID : 5e197fe2:5c51970e:5e5288d5:e9066eb4 Events : 17 Number Major Minor RaidDevice State 0 8 49 0 active sync /dev/sdd1 1 8 50 1 active sync /dev/sdd2 2 8 51 - spare /dev/sdd3
5) 在raid设备上创建文件系统并挂载
[root@centos7-xinsz08 ~]# mkfs.xfs /dev/md2meta-data=/dev/md2 isize=512 agcount=4, agsize=196288 blks = sectsz=512 attr=2, projid32bit=1 = crc=1 finobt=0, sparse=0 data = bsize=4096 blocks=785152, imaxpct=25 = sunit=0 swidth=0 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@centos7-xinsz08 ~]# mkdir /raid1[root@centos7-xinsz08 ~]# mount /dev/md2 /raid1/[root@centos7-xinsz08 ~]# df -h | tail -1/dev/md2 3.0G 33M 3.0G 2% /raid1
6) 创建测试文件,看如果一块磁盘坏掉,数据是否丢失
[root@centos7-xinsz08 raid1]# touch a.txt[root@centos7-xinsz08 raid1]# echo "磁盘坏了,我也在" >a.txt
7) 模拟损坏(sdd1盘坏掉了)
[root@centos7-xinsz08 raid1]# mdadm /dev/md2 -f /dev/sdd1mdadm: set /dev/sdd1 faulty in /dev/md2[root@centos7-xinsz08 raid1]# mdadm -D /dev/md2/dev/md2: Version : 1.2 Creation Time : Thu Feb 27 16:24:39 2020 Raid Level : raid1 Array Size : 3140608 (3.00 GiB 3.22 GB) Used Dev Size : 3140608 (3.00 GiB 3.22 GB) Raid Devices : 2 Total Devices : 3 Persistence : Superblock is persistent Update Time : Thu Feb 27 16:31:48 2020 State : clean, degraded, recovering Active Devices : 1 Working Devices : 2 Failed Devices : 1 Spare Devices : 1 Consistency Policy : resync Rebuild Status : 88% complete Name : centos7-xinsz08:2 (local to host centos7-xinsz08) UUID : 5e197fe2:5c51970e:5e5288d5:e9066eb4 Events : 35 Number Major Minor RaidDevice State 2 8 51 0 spare rebuilding /dev/sdd3 1 8 50 1 active sync /dev/sdd2 0 8 49 - faulty /dev/sdd1
测试移除之后文件是否还在
[root@centos7-xinsz08 raid1]# cat /raid1/a.txt 磁盘坏了,我也在
8) 移除坏掉的设备,同时另外加一个备份盘
[root@centos7-xinsz08 raid1]# mdadm -r /dev/md2 /dev/sdd1mdadm: hot removed /dev/sdd1 from /dev/md2 ``查看是否移除```bash[root@centos7-xinsz08 raid1]# mdadm -D /dev/md2/dev/md2: Version : 1.2 Creation Time : Thu Feb 27 16:24:39 2020 Raid Level : raid1 Array Size : 3140608 (3.00 GiB 3.22 GB) Used Dev Size : 3140608 (3.00 GiB 3.22 GB) Raid Devices : 2 Total Devices : 2 Persistence : Superblock is persistent Update Time : Thu Feb 27 16:34:10 2020 State : clean Active Devices : 2 Working Devices : 2 Failed Devices : 0 Spare Devices : 0 Consistency Policy : resync Name : centos7-xinsz08:2 (local to host centos7-xinsz08) UUID : 5e197fe2:5c51970e:5e5288d5:e9066eb4 Events : 39 Number Major Minor RaidDevice State 2 8 51 0 active sync /dev/sdd3 1 8 50 1 active sync /dev/sdd2
9) 增加一块热备盘
mdadm -a /dev/md2 /dev/sdb4
总结:
- raid1中一块硬盘坏了不影响raid正常运行
- 使用率是50%
标签:root,dev,centos7,raid1,Devices,linux,xinsz08,mdadm 来源: https://blog.51cto.com/xinsz08/2706423