I know RAID 1 is mirror, RAID 10 is RAID 0+RAID 1. Yet I found that with same 8 disks on IBM Server, I can format RAID 10 for those 8 disks or RAID 1 for 8 disks. Both options allows to use 8/2 = 4 disks’ spaces. In Mega RAID Controller software, we can see RAID 10, there’re 4 couples of disks in 1 logical disk while RAID1 includes all of 8 disks in 1 logical disk.
So I don’t know what does RAID1 for 8 disks in this case mean ? And how about the performance comparing to RAID10 ?
RAID 1 = Mirror, so with 8 disks there are 4 mirroring (exact copies of) the other 4. The 4 would probably be JBOD, so as one fills up, files would spill onto the next
RAID 10 = Mirror of stripes, so 4 drives are striped (data is broken into 4 chunks and written to 4 drives at the same time, then the result is mirrored – considerably better performance than RAID1
(someone will tell me it is actually a stripe of mirrors, but the result is the same