What To Do When Your Synology NAS Drive Crashed – Bad Sector Exceed Limits


Less than two years in work, my Synology NAS experienced its first crash. I woke up one day and walked into the office found the NAS just keeps beeping none stop. The next thing I did was log on to the server, and surprisingly it still worked. This post is mainly me documenting what happened, what didn’t happen and what can be done to prevent or prolong an eventual hard drive failure with your Synology NAS.

Here is a little background. It all started around September 2015, there was a post on why I made the decision in purchasing this NAS. Both hard drives are brand new, however, they aren’t designed or yet optimized to be used in a NAS and I used them in NAS regardless.

If you are still able to login to your NAS while it’s beeping that means not all your drives has failed. Chances are there is only one drive has failed. If you have SHR (Synology Hybrid RAID) or regular RAID (1 or higher configured) your data stays intact.

In my case, I was able to log in and discover there were multiple bad sectors found on one of the hard drives. By default, Synology’s bad sector threshold limit is set to 1, which means if there are more than one bad sectors on the hard drive you will receive warning notifications. If Synology is configured to receive email notifications this is what you will be receiving.

Dear user,
The bad sectors on disk 2 on DS215j exceeded the limit value of 1.  This disk may still be working and healthy. We recommend you to make sure that your data has been properly backed up. You can also ignore or disable this value, or reconfigure it on DSM.
S.M.A.R.T. status: Normal
IronWolf Health Management: –
Bad sector count: 15
Disk reconnection count: 0
Disk re-identification count: 0
SSD estimated lifespan: –

If you see one of the volumes has crashed under Storage Manager, there is a repair link that will launch “Disk Scan Notification” and it will scan and attempt to repair bad sectors.

Depends on the size of your drive this repair process will take a long time. While it’s repairing you can use Synology Assistant to track and monitor the progress.

After checking file system is completed you can go to the Storage Manager > Health Info > History to check any historical event such as the number of new bad sector found in a given month.

Looking at the history, it appears the first time when bad sectors reported on the system was dated back on last November. If according to this chart, the bad sector started well over couple months ago, but unfortunately email notification stopped working around the same time. No alerts were ever sent out.

To fix the Synology not sending out emails issue, go to Control Panels > Notification > Email. Log out of Gmail or the Service provider of your choice. Re-authorize the mail service provider with Synology again. This will reconnect your NAS to the mail service and able to send email alerts to yourself.

Hard drives are something that’s physically spinning, they are mechanical. Anything mechanical will eventually break. There is no secret to prevent such ever happen, you will eventually run into bad sectors on your hard drive regardless of the type of hard drive you choose. However, there are ways you can prolong your hard drive life span. We’ve covered in one of the top 5 things to do with your new Synology NAS that is to put the hard drive into hibernation mode as much as possible. By reduce the length of operation, you can thus prolong your hard drive life.


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