Checking RAID Status with mdadm
Overview
I’m currently running software RAID 1 on some ubuntu workstations. At tool to monitor the status of the RAID is mdadm.
Usage
Get Information about a multi-disk partition
mdadm --detail /dev/md0
Output
/dev/md1:
Version : 00.90
Creation Time : Sun Feb 17 12:45:34 2008
Raid Level : raid1
Array Size : 146480576 (139.69 GiB 150.00 GB)
Used Dev Size : 146480576 (139.69 GiB 150.00 GB)
Raid Devices : 2
Total Devices : 2
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : Mon Jun 15 09:57:54 2009
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
UUID : 36a0291e:88bead7c:e810d6ed:3bf4dde3
Events : 0.76
Number Major Minor RaidDevice State
0 8 2 0 active sync /dev/sda2
1 8 18 1 active sync /dev/sdb2
Interpretations
I have two RAID devices that are active, working and in a clean state. This is what I want.
Show Information for All Multi-disk Partitions
cat /proc/mdstat
Output
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md1 : active raid1 sda2[0] sdb2[1]
146480576 blocks [2/2] [UU]
md0 : active raid1 sda1[0] sdb1[1]
48829440 blocks [2/2] [UU]
unused devices:
Interpretations
Two multi-disk arrays active.
Showing changes from previous revision. Removed | Added
