I recently lost a 2TB hard drive after less than 2 months of operation. Newegg is giving me a full refund and is paying for return shipping, so I want to replace the 2TB drive with a RAID 5 configuration. The motherboard is a XFX GeForce 9300 mGPU, which claims to support RAID 5. I am not sure whether to go with the software RAID supported by my motherboard or a dedicated hardware raid card. Which I do comes down to the following points and I was hoping people here could help me fill in the blanks.
Can I replace the drive and rebuild the array while the system is running?
Does the RAID controller provide guarantees that a powerloss or system crash will not leave the drives in an inconsistent state? i.e. If you do two writes to the array, will there be at any point in time a state where some drives reflect write A, but not write B while other drives reflect write B, but not write A?
If the controller should die or I should need to move the drives to another system, how easy would it be for me to connect the drives to another system and still be able to access my data? i.e. Is the striping and parity data done in a way that makes controllers interchangeable?
If I want more storage in the future, will I be able to add drives to the array and then have the drives I added appear as unpartitioned space to the OS? Can that be done while the system is running?
I am concerned about error recovery causing drives to fall out of the array. I know that Western Digital has a TLER feature that avoids that, but it is expensive. Is there any way that I can address that concern while keeping costs low?
Also, I have read about an automatic head parking feature that is present in new drives that could cause them to fail prematurely. Is there any way to disable that feature on drives that have it or will I need to find drives that do not have it?
Since I have not committed to using my motherboard to implement RAID 5, does anyone have any suggestions for dedicated RAID 5 controllers that address my concerns? I am not necessarily set on using SATA drives, so if there are any advantages to getting a controller for SCSI or SAS drives, I would consider possibly using those drives instead.