MdAdm monitoring
by Gisle Hannemyr
[TBA]
Table of contents
Introduction
DegradeArray event
When a defective RAID array is detected, you will get an email like this:
Date: Sun, 19 Apr 2020 07:37:57 +0200 (CEST)
From: mdadm monitoring <root@example.com>
To: root@example.com
Subject: DegradedArray event on /dev/md/0:xyz.com
This is an automatically generated mail message from mdadm
running on pvn.no
A DegradedArray event had been detected on md device /dev/md/0.
Faithfully yours, etc.
P.S. The /proc/mdstat file currently contains the following:
Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10]
md0 : active raid1 sda1[0]
488253248 blocks super 1.2 [2/1] [U_]
unused devices: <none>
From message you can read which Raid array is affected. Here it is
Now look deeper and understand the content of md0 block.
md0 is active and uses raid1. The array is build with disk sda1.
[U_] does mean, one of the drives is not synced.
However, this disc is not marked with a (F).
To get more details of the degraded array, use this command:
$ sudo mdadm --detail /dev/md0
/dev/md0:
Version : 1.2
Creation Time : Sat Feb 2 12:28:33 2013
Raid Level : raid1
Array Size : 488253248 (465.63 GiB 499.97 GB)
Used Dev Size : 488253248 (465.63 GiB 499.97 GB)
Raid Devices : 2
Total Devices : 1
Persistence : Superblock is persistent
Update Time : Tue Apr 21 10:56:39 2020
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Name : bar:0
UUID : cbb19dd9:5519aa64:25a091c6:fa7103e4
Events : 34620651
Number Major Minor RaidDevice State
0 8 1 0 active sync /dev/sda1
2 0 0 2 removed
Final word
[TBA]
Last update: 2020-02-28 [gh].