I have a Synology Diskstation 412+ NAS in my home office that is nearly full. The NAS was purchased November of 2012 and has 4 Western Digital 2TB Red drives configured in RAID 6. I am currently using 3.2 out of the 3.6 TB capacity (89%) and need to increase the capacity to 6-10 TB.
When I purchased the NAS it was being used for both work and home files. The work files involved backing up a web server, a file server and 1 workstation while the home files included pictures and videos. I decided to configure the drives in RAID6 so that I could weather up to two drive failures. In the past 5 years I had one drive go bad and the replacement was super easy with no data loss or downtime. I also have a new spare 2TB Red drive in a box in case another drive fails.
My work situation has changed and I no longer need to be able to handle two simultaneous disk failures. In order to keep my RAID 6 and increase my capacity, I think I have to replace all four drives. If I was starting out today, I would rather have two 8TB drives mirrored and have a third 8TB drive available for a spare. I am looking for advice on the best way to expand my capacity while not breaking the bank. FYI, I purchased a Western Digital 8TB EasyStore external drive that I will use to backup the NAS before I make any changes. I currently backup my NAS volumes to multiple smaller drives.
Here are the options I am considering:
1. Reconfigure current 4x2TB system to RAID 5 increasing capacity to 6TB
- Benefits: No out of pocket cost. Also already have spare 2TB drive on hand in case one drive fails.
- Drawbacks: 1) must "rebuild NAS" meaning: first backup entire NAS, reformat drives into RAID 5, recreate volumes, and copy all data back to NAS, 2) only yields a 2TB increase in capacity, so likely short-term solution, 3) if NAS fails must rely on backup to avoid data loss
2. Purchase two new 8TB Red drives, mirroring them to get 8TB capacity and leaving two bays empty.
- Benefits: 1) doubles capacity to 8TB which should be enough for multiple years, 2) data now stored on two brand new drives (presumably more reliable), 3) simple mirroring means if NAS dies I can recover files off of either drive in case backup not current
- Drawbacks: 1) will cost about $500, 2) must rebuild NAS
3. Maintain RAID 6 and upgrade all drives to 4TB Reds to double capacity to 8TB.
- Benefits: 1) I think there is no need to rebuild NAS, with hot swap I think I can swap one drive at a time and end up with 8TB capacity RAID 6 NAS
- Drawbacks: 1) will cost about $600 for 4x4TB or $820 for 4 x 6TB with no spare drive on hand, 2) if NAS fails must rely on backup to avoid data loss
I am leaning towards Option 2 unless experts think that my Synology hardware is nearing its end of life. If I am going to likely need a new NAS in the next 12-24 months, I may go with Option 1 and wait until the NAS fails. When it does, buy a two bay NAS thinking by then cost of NAS and drives will be lower.
I am looking for advice on the best approach as well as suggestions on best way to backup NAS if I end up choosing Option 1 or 2. Please let me know if you have any questions.