您好，从 Hetzner 订购了一台服务器，并为服务器添加了一个 500GB SSD。运行了安装程序映像，但我不确定软件 Raid 是否在我的所有三个硬盘上都有效。我如何才能将软 Raid 也添加到新添加的 SSD 中？
我不介意重新安装服务器。
硬盘我有 2 x 1TB SATA 1 x 500GB SSD
这是我的配置
df -h 输出
[root@CentOS-610-64-minimal ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/md2 906G 886M 859G 1% /
tmpfs 16G 0 16G 0% /dev/shm
/dev/md1 496M 35M 436M 8% /boot
[root@CentOS-610-64-minimal ~]#
fdisk -l 输出
[root@CentOS-610-64-minimal ~]# fdisk -l
Disk /dev/sdb: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xca606b93
Device Boot Start End Blocks Id System
/dev/sdb1 1 2089 16777216 fd Linux raid autodetect
/dev/sdb2 2089 2155 524288 fd Linux raid autodetect
/dev/sdb3 2155 62261 482804056 fd Linux raid autodetect
Disk /dev/sdc: 512.1 GB, 512110190592 bytes
255 heads, 63 sectors/track, 62260 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x8b577ece
Device Boot Start End Blocks Id System
/dev/sdc1 1 2089 16777216 fd Linux raid autodetect
/dev/sdc2 2089 2155 524288 fd Linux raid autodetect
/dev/sdc3 2155 62261 482804056 fd Linux raid autodetect
Disk /dev/sda: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x595cad86
Device Boot Start End Blocks Id System
/dev/sda1 1 2089 16777216 fd Linux raid autodetect
/dev/sda2 2089 2155 524288 fd Linux raid autodetect
/dev/sda3 2155 62261 482804056 fd Linux raid autodetect
Disk /dev/md1: 536 MB, 536805376 bytes
2 heads, 4 sectors/track, 131056 cylinders
Units = cylinders of 8 * 512 = 4096 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/md0: 17.2 GB, 17179738112 bytes
2 heads, 4 sectors/track, 4194272 cylinders
Units = cylinders of 8 * 512 = 4096 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/md2: 988.8 GB, 988782002176 bytes
2 heads, 4 sectors/track, 241401856 cylinders
Units = cylinders of 8 * 512 = 4096 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 524288 bytes / 1048576 bytes
Disk identifier: 0x00000000
cat /proc/mdstat 输出
[root@CentOS-610-64-minimal ~]# cat /proc/mdstat
Personalities : [raid1] [raid6] [raid5] [raid4]
md2 : active raid5 sda3[0] sdb3[1] sdc3[3]
965607424 blocks super 1.0 level 5, 512k chunk, algorithm 2 [3/3] [UUU]
bitmap: 0/4 pages [0KB], 65536KB chunk
md0 : active raid1 sda1[0] sdb1[1] sdc1[2]
16777088 blocks super 1.0 [3/3] [UUU]
md1 : active raid1 sda2[0] sdb2[1] sdc2[2]
524224 blocks [3/3] [UUU]
unused devices: <none>
mdadm -D /dev/md0 输出
[root@CentOS-610-64-minimal ~]# mdadm -D /dev/md0
/dev/md0:
Version : 1.0
Creation Time : Sat Oct 6 04:49:31 2018
Raid Level : raid1
Array Size : 16777088 (16.00 GiB 17.18 GB)
Used Dev Size : 16777088 (16.00 GiB 17.18 GB)
Raid Devices : 3
Total Devices : 3
Persistence : Superblock is persistent
Update Time : Sat Oct 6 06:02:45 2018
State : clean
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
Name : rescue:0
UUID : b4cf051f:22b30734:e45d5bca:cfff80e8
Events : 21
Number Major Minor RaidDevice State
0 8 1 0 active sync /dev/sda1
1 8 17 1 active sync /dev/sdb1
2 8 33 2 active sync /dev/sdc1
mdadm -D /dev/md1 输出
[root@CentOS-610-64-minimal ~]# mdadm -D /dev/md1
/dev/md1:
Version : 0.90
Creation Time : Sat Oct 6 04:49:31 2018
Raid Level : raid1
Array Size : 524224 (511.94 MiB 536.81 MB)
Used Dev Size : 524224 (511.94 MiB 536.81 MB)
Raid Devices : 3
Total Devices : 3
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : Sat Oct 6 04:53:41 2018
State : active
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
UUID : f1fd684a:98b3c1eb:776c2c25:004bd7b2
Events : 0.23
Number Major Minor RaidDevice State
0 8 2 0 active sync /dev/sda2
1 8 18 1 active sync /dev/sdb2
2 8 34 2 active sync /dev/sdc2
mdadm -D /dev/md2 输出
[root@CentOS-610-64-minimal ~]# mdadm -D /dev/md2
/dev/md2:
Version : 1.0
Creation Time : Sat Oct 6 04:49:37 2018
Raid Level : raid5
Array Size : 965607424 (920.88 GiB 988.78 GB)
Used Dev Size : 482803712 (460.44 GiB 494.39 GB)
Raid Devices : 3
Total Devices : 3
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Sat Oct 6 11:02:41 2018
State : clean
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Name : rescue:2
UUID : 6ebb511f:a7000ca5:c98b1501:4d2b3707
Events : 1330
Number Major Minor RaidDevice State
0 8 3 0 active sync /dev/sda3
1 8 19 1 active sync /dev/sdb3
3 8 35 2 active sync /dev/sdc3
Hetzner 安装程序映像文件
DRIVE1 /dev/sda
DRIVE2 /dev/sdb
DRIVE3 /dev/sdc
SWRAID 1
SWRAIDLEVEL 5
PART swap swap 16G
PART /boot ext3 512M
PART / ext4 all
答案1
您的输出显示您有 2*2TB 磁盘，并且有一个 RAID5 和两个 RAID1。
md2 : active raid5
md0 : active raid1
md1 : active raid1
正如评论中所提到的，RAID5 中的一个 SSD 与两个传统磁盘放在一起并没有多大意义。
我建议使用 SSD 和旋转磁盘设置为主要写入的 RAID1。
您使用 SSD 和另外两个磁盘的 500MB 选项创建 RAID1 --bitmap=internal /dev/ssd --write-mostly --write-behind /dev/disk1 /dev/disk2。请参阅man mdadm以了解详细信息。
这会将所有内容写入 SSD，最终写入旋转磁盘。除非 SSD 发生故障，否则将从快速 SSD 读取数据，只有这样才会从其他磁盘读取数据。如果 SSD 发生故障，您可以从 SSD 以及其他磁盘上的镜像快速读取和写入数据。
旋转磁盘上的另外 1.5GB 可以组合成另一个 RAID1，用于不需要快速访问且不适合 0.5GB SSD RAID 的数据。