Raid 5 with 4 disks on Debian automatically creates a spare drive
- by Razer
I'm trying to to create a RAID 5 with 4x 2TB disks on Debian 6. I followed the instructions from: http://zackreed.me/articles/38-software-raid-5-in-debian-with-mdadm
I created the raid with following command: sudo mdadm --create --verbose /dev/md0 --auto=yes --level=5 --raid-devices=4 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
After creating the RAID mdadm --detail /dev/md0 shows me:
/dev/md0:
Version : 1.2
Creation Time : Mon Jun 11 18:14:26 2012
Raid Level : raid5
Array Size : 5860535808 (5589.04 GiB 6001.19 GB)
Used Dev Size : 1953511936 (1863.01 GiB 2000.40 GB)
Raid Devices : 4
Total Devices : 4
Persistence : Superblock is persistent
Update Time : Mon Jun 11 18:14:26 2012
State : clean, degraded
Active Devices : 3
Working Devices : 4
Failed Devices : 0
Spare Devices : 1
Layout : left-symmetric
Chunk Size : 512K
Name : rsserver:0 (local to host rsserver)
UUID : a68c3c99:1ef865e9:5a8a7bdc:64710ed8
Events : 0
Number Major Minor RaidDevice State
0 8 17 0 active sync /dev/sdb1
1 8 33 1 active sync /dev/sdc1
2 8 49 2 active sync /dev/sdd1
3 0 0 3 removed
4 8 65 - spare /dev/sde1
Why is there a spare drive? I didn't create one. I don't want to use a spare drive.