I didn’t get you can you brief you answer @Carlosdl
1 drive for parity, 4 drives for data. 4 x 250GB
but RAID-5 uses pair of 3 hdd then how it will use 4 drive for data
I’m not sure to understand your last question.
You need at least 3 disks for a RAID 5 configuration, but that doesn’t mean that you need a number of disks that is a multiple of 3.
Standard RAID levels at Wikipedia.
yeah minimum is 3 disk for raid 5..