Synology Disk fail: How to replace RAID online

What happens when one of the RAID disks fails? Well first a bit of disappointment and then yes, what about the data? Luckily recovering from a Synology disk fail on the RAID couldn’t be any easier and the entire process if wizard driven. Including the default “beeping” as soon as one of the disks have crashed and the performance on the RAID are degraded. All in all this set of drives have been purchased about 5 years ago and this is the first one failing. Well at the time of writing this article other two drives failed and have been already replaced. So out of the initial 4 only one is standing!

Different RAID systems offer different performances and fault tolerance. In this case the Synology DS416Play is doing an excellent job on performance with a RAID 10 and with 2 disk failures supported. It is running primarily as a backup target and to support backup of applications like a secondary DNS and Syslog server for VMware VCSA appliance and other applications.

The entire process is very simple and all it requires is to follow the steps on the wizard to completion. The screenshots below show the main steps.

Repair Synology Disk fail

If not already beeping, the action center on the Synology desktop will show an alert about the volume degraded. This can be the symptom of the Synology disk fail on the RAID or maybe just some bad sectors found due to a scrubbing routine. In both cases it is highly recommended to replace the drive with the same or a similar one at least in size or higher and speed.

An additional message in the notification also shows the volume on the Synology is low on capacity.

By browsing the Storage Manager utility, the main dashboard shows the compromised volume and the affected physical drive.

In the Volume section more info and pointer to the KB article which provides the details about replacing the faulty drive.

In a similar fashion also the Storage Pool section reports on the crashed drive.

The Storage Pool section offers tools like the Data Scrubbing (which is also scheduled by default) to help finding bad sectors or if the disk is completely dead.

In the configuration section also the option to help rebuild the RAID, assuming the disk can still work and waiting for a replacement.

Unfortunately after almost 5 years of 24/7 activity the disk has crashed. For the “die hard” there are also S.M.A.R.T. tests that can be done from the HDD/SSD section.

If none of the previous checks was able to verify the drive, it is now time to deactivate the Synology disk fail on the RAID and replace with a new one.

Next is to accept the warning about removing the drive from the associated Storage Pool.

At this point it is possible to insert the new drive on the bay. This is highlighted with a different led blinking.

The new disk is recognized which is a good starting point. This is necessary to “initialize” the disk and associate this to the existing RAID.

In the Storage Pool section and Action > Repair the wizard will begin the association for new disk.

It is a matter of confirming the single or multiple drives when adding more at the same time.

At this point confirm all data on the new drive will be erased and ok to continue.

A final screen to review and confirm the changes and also report the final new capacity which is the same as before the disk failure happened.

This process can take quite a long time and of course depending on CPU/Mem resources available on the Synology Disk station and of course the size of the new disk.

Upon completion a new set of messages in the notification center are more reassuring and the RAID rebuild has completed successfully.

And a final view on the HDD/SSD section shows the healthy status along with other details for the new drive.