最近拿到的几个12块盘的服务器，都是没有RAID卡的。自己就简单做了一下软RAID。
- 用/dec/sd[b-l]1创建一个raid10的/dev/md1，其中一个做备用盘。
mdadm –create /dev/md1 –run –level=10 -n 10 /dev/sd[b-l] -x 1 mkdir /mnt/data ; mkfs.ext4 /dev/md1 2.把mda1加到fstab/dev/md1 /mnt/data ext4 defaults,noatime 0 03.把阵列信息加到/etc/mdadm.confmdadm –detail –scan » /etc/mdadm.conf
状态查看可以
#cat /proc/mdstat Personalities : [raid10]
md1 : active raid10 sdl[10](S) sdk[9] sdj[8] sdi[7] sdh[6] sdg[5] sdf[4] sde[3] sdd[2] sdc[1] sdb[0]
9767564800 blocks super 1.2 512K chunks 2 near-copies [10/10] [UUUUUUUUUU]
unused devices:
#mdadm –detail /dev/md1 /dev/md1: Version : 1.2 Creation Time : Sat Jul 20 00:33:49 2013 Raid Level : raid10 Array Size : 9767564800 (9315.08 GiB 10001.99 GB) Used Dev Size : 1953512960 (1863.02 GiB 2000.40 GB) Raid Devices : 10 Total Devices : 11 Persistence : Superblock is persistent
Update Time : Sat Jul 20 08:33:55 2013 State : active Active Devices : 10 Working Devices : 11 Failed Devices : 0 Spare Devices : 1
Layout : near=2 Chunk Size : 512K
Name : xxx UUID : xxx Events : 18
Number Major Minor RaidDevice State 0 8 16 0 active sync /dev/sdb 1 8 32 1 active sync /dev/sdc 2 8 48 2 active sync /dev/sdd 3 8 64 3 active sync /dev/sde 4 8 80 4 active sync /dev/sdf 5 8 96 5 active sync /dev/sdg 6 8 112 6 active sync /dev/sdh 7 8 128 7 active sync /dev/sdi 8 8 144 8 active sync /dev/sdj 9 8 160 9 active sync /dev/sdk
10 8 176 - spare /dev/sdl
单个盘的操作1.卸掉故障盘mdadm /dev/md1 -f /dev/sddmdadm /dev/md1 -r /dev/sdd2.恢复单个盘mdadm –zero-superblock /dev/sddmdadm /dev/md1 -a /dev/sdd3.停掉整个RAIDmdadm –stop /dev/md14.启动整个RAIDmdadm -A /dev/md1
简单测试了一下RAID的性能和单个盘的性能差别
RAID10： #dd if=/dev/zero of=test1 bs=1024000 count=10240 oflag=direct ;sleep 5; dd if=test1 of=/dev/null bs=1024000 count=10240 iflag=direct 10240+0 records in 10240+0 records out 10485760000 bytes (10 GB) copied, 20.4646 s, 512 MB/s 10240+0 records in 10240+0 records out 10485760000 bytes (10 GB) copied, 15.0176 s, 698 MB/s
单个盘： #dd if=/dev/zero of=test1 bs=1024000 count=10240 oflag=direct ;sleep 5; dd if=test1 of=/dev/null bs=1024000 count=10240 iflag=direct 10240+0 records in 10240+0 records out 10485760000 bytes (10 GB) copied, 62.761 s, 167 MB/s 10240+0 records in 10240+0 records out 10485760000 bytes (10 GB) copied, 61.865 s, 169 MB/s
做了RAID后读取的是基本是把SAS卡的6G的带宽跑满了，写入也有三倍左右的提升。