Checking Software RAID Status

This guide shows how to check the status of a Linux software RAID (mdadm) on your dedicated server via /proc/mdstat and how to set up automatic email alerts for a failed drive.

Note: A RAID array protects against hardware failure but does not replace a regular backup of your data on external media.

Manual Check via /proc/mdstat

Check the real-time status of your software RAID arrays directly through the system:

Check RAID Status

cat /proc/mdstat

Understanding the Output

Healthy Array [UU]

In a RAID 1 setup, [UU] indicates that both drives are active and synchronized.

Example: OK

md0 : active raid1 sdb1[0] sda1[1] 104320 blocks [2/2] [UU]

Degraded Array

A status such as [_U] means a disk is missing or defective. The _ character serves as a placeholder for the failed drive.

Example: Degraded

md1 : active raid1 sdb3[1] 154143552 blocks [2/1] [_U]

Set Up Email Alerts

Step 1: Set Recipient

Add your email address to the configuration file (Debian/Ubuntu: /etc/mdadm/mdadm.conf, AlmaLinux/Rocky Linux: /etc/mdadm.conf):

Open configuration

nano /etc/mdadm/mdadm.conf

Add the following line:

MAILADDR [email protected]

Step 2: Start Monitoring

Restart the monitoring service so it picks up the new address, then send a test alert:

Service control

systemctl restart mdmonitor.service systemctl status mdmonitor.service mdadm --monitor --scan --test --oneshot

For emails to be sent, an MTA (e.g., Postfix) must be active on the server.

Contact Support

If you have confirmed a hardware defect, we will replace the drive immediately. Please open a ticket in the PowerPanel.

Go to PowerPanel