From Kb_JMY(晉明夷)

Synology Diskstation: DS210j

• Synology.com -- DS210j Specifications
• forum.synology.com

• SynologyNAS: How to promote DS210j from Basic Mode (1disk) to RAID1(2disks)?

Repairing the Diskstation: RAID1 with one harddisk bad

• symptom: Continuous BEEP sound emitted by the DS210j (at interval of 1 to 2secs)
• volume status: Volume1 degraded

Repairing procedure (w/o opening the enclosure)

• login the Diskstation Manager, e.g. DMS3.0

-> in Firefox, enter http://192.168.1.100:5000

-> or http://hlhnas:5000

-> login as admin

-> go control panel -> Storage Manager

• identifying the bad harddisk

• click HDD Management and you may find "disk2" status: Abnormal
• click Disk info and it may display something like:

Disk model: ST31000528AS (i.e. Seagate 1TB Harddisk)
serial#: 6VP470KA
Firmware: CC38
Total size: 931.51GB

• Repairing the bad hardisk w/o opening the enclosure

-> click volume -> manage -> repair

-> choose the bad disk, say, disk2 (double check! OR all data be LOST!)

-> start the repair and be patient to wait -- this may take 3-4hours for a 1TB drive!

-> check the progress from "volume > properties > status"

-> it may look like this after 1 hour: repairing (checking parity consistence, 23.66%)