Hi, with this there's only so much we can help, it's really all down to the customer (you)- whether the file is (if it's read first, or do a lot of writes, whether the file is a big, or if you have a lot of small files and etc..) The customer has to do it himself/herself at the end of the day.[URL] Sorry I can't be of much help this time.
I have a Dell PowerEdge T320 that is running RAID 5 with three Dell Savvio 10K.6 300GB HDDs using the Dell PERC H710 SCSI controller. I was originally going to add a 4th drive to this setup, and be done with it. But after much reading, it seems RAID 5 is not recommended anymore and has supposedly been deprecated. So, I would like to migrate to RAID 10, which requires four drives, so I will still need to add this drive to my current RAID 5. I would like to confirm the above RAID controller is in fact capable of performing migration from RAID 5 with four disks to RAID 10. I understand many will likely suggest I shouldn't stress the drives by doing it in this fashion, but rather should just start from scratch and create the RAID 10, and then reinstall everything. If I could just restore my system backup onto a newly created RAID 10, that would be fine, but my current system backup is of the current RAID 5 with 3 drives, so I'm assuming this would not work, though after thinking about it, I suppose it should work. I guess I'm more afraid there is more to it as I'm still learning about RAID.  
Can I Migrate From RAID 5 to RAID 10 After Adding a 4th Drive to my RAID 5