I've a ReadyNas 104 with 2x1TB and 1x500GB HDD X-RAID mode (RAID5). Now I'm planning to buy a new HD, I'm thinking about a 2TB or a 2TB WD RED. Probably in a few months I'll buy another one in order to replace the old 500GB. The question is: which is the best choice for the new HDD: 2x3TB or 2X2TB associated with the actuals 2X1TB? I think the configuration will remain RAID5 (or with 4 HDD RAID6). I have only one volume and I don't plan to create multiple volumes. Thanks a lot!
If you are thinking RAID-6 you should also upgrade the 2x1 TB, otherwise your volume size is limited to 2TB. I'd stick with RAID-5 (and make backups!)
Usually I start by figuring out which choice is most cost effective (incremental storage gain / cost). Then temper that with any budget constraints... If it is close, I go with the larger size if it is affordable.
Current prices (US) make the 3 TB model the most cost-effective Red drive for this particular project.
10.71 GB/$ for 2x1 TB Red (gains 1500 GB more storage for $140) 12.75 GB/$ for 2x2 TB Red (gains 2500 GB more storage for $200) 14.58 GB/$ for 2x3 TB Red (gains 3500 GB more storage for $240) 9.45 GB/$ for 2x4 TB Red (gains 4500 GB more storage for $370)
I'd go with a NAS drive (either WDC or Seagate), since they have 3-year warranties, and the drive manufacturers will fully support NAS applications. Consumer drives generally have 1 year warranties.
