I'm looking to replace my existing RAID array. It's a 4x500 GB RAID 5 array with WD RE2 drives (1.5TB array).
I'd also like to get my data off some non-RAID drives (1.5TB Seagate 5400rpm and a 1TB WD Black) and onto a RAID.
So this brings me to requiring a 4 TB array. Speed is not a concern since I use a SSD for boot/OS/programs, and the array won't be running 24/7 - I'm just looking for some protection from a single drive failure. To me, it seems my options are:
3x2TB RAID 5 for a yield of 4 TB - $299.22 (incl. tax)
3x3TB RAID 5 for a yield of 6 TB - $440.97 (incl. tax)
2x4TB RAID 1 for a yield of 4 TB - $587.98 (incl. tax)
I can't afford to get RE4 drives, so I'm looking for the next-best alternative.
2TB drives (Seagate Barracuda 7200rpm 64MB cache SATA 3 drives (ST2000DM001)) would be the cheapest. 2TB WD Red drives are fairly cheap too, so I would consider those - not sure if they're ideal for use in a desktop rather than a NAS though, and they haven't been around long enough to see if there are any major problems.
Going to 3TB drives is an option, but I don't see myself requiring more than 4TB of total storage in the near future (and if I do I can always put less critical stuff on a single cheap drive). The 3TB drives could be Seagates as well, or WD Reds.
Going to 4TB simplifies things in that it's only 2 drives in a RAID 1, rather than dealing with parity calculations etc on a RAID 5, but the cost is almost double the 3x2TB RAID 5.
What is my best option? Go with the cheap Seagate 2TBs? Spend the extra for the WD Reds? Is there another drive or configuration I should be looking at?
I see not reason not to go for your first option. You're already using and familiar with RAID5, so I think the simplicity of RAID1 is worth twice the cost. Unless your having problem with your existing RAID5 implementation or are considering a new card, I see no reasons listed to change it. You basically talked yourself out of option 2, but you could consider 4x1.5TB RAID5, more space and cheaper than option 1.