What are the benefits of DrivePool over Raid 5

madmax555

I'm coming from WHS v1 and the lost of drive extender, is unfortunate.  I have four 1 TB drives and looking for a solution for redundancy of my information.    It seems like drive pool  would be more beneficial over Raid 5 on which I have three drives in Raid 5 using Disk Management in Windows.  It leaves me with just under 2 TB which I believe because of the 33 percent parity when the raid is constructed.  Using drive pool (duplication) though is pretty much a 50 percent loss if you have fill up the drive, right?  Should I just go a hardware raid?  I'm using small factor Acer H340 so I have only limited choices with one PCIx slot to work with otherwise I would have gone that way already but at the same time i probably would have a chip set raid if I had a bigger mobo. Some suggestions! 

Shane

3-Drive RAID5: 33% overhead. Block striping means if machine dies, must use another machine with exact same block striping method to read it. Fast reads, slow to very slow writes. Error checking, parity reconstruction. If two drives fail (or a second fails while first is rebuilding - I've had this happen) all is lost. Depending on what software/hardware is providing the RAID5, adding another drive may require rebuilding the entire array.

3-Drive DP: 50% overhead on shares that have duplication enabled. File-level means if machine dies, any machine that can read NTFS disks can read files. Normal reads, normal to slow writes. Error checking, no parity reconstruction (if one's bad and one's good, it drops the bad one and recreates from the good, but if both are bad or if it can't determine which is bad then it doesn't have a parity record to use to repair the damage). If two drives fail you still have whatever was on the third. Adding another drive is as simply as plugging it in and telling DP to add it.

DP's framework is such that it's feasible to add parity support if there's sufficient demand for that feature, but right now it doesn't have it.

DP is "basically" a user-friendly on-demand hardware-agnostic plug-and-expand share-level RAID1.