We have a server that has 5 SCSI disks.
Normally, we create one RAID 1 mirrored paired for the OS (disks 0 and 1), and then the remaining 3 are used in a RAID 5 setup for the application.
However, I was thinking about this....what's the actual advantage of having the OS on a mirrored pair. Surely, if all 5 disks were in a RAID 5, then we could lose one anyway? Why the seperation?
Secondly, can one Array Controller service as many disks into different RAID configurations as needed? I.e. will one Array Controller be sufficient for the above in a RAID 1 and RAID 5 setup?
Finally, out of RAID 1 and RAID 5, which one is better for an application that writes a lot, and which one is better for an application that reads a lot?
I'm not a hardware person at all, so any help appreciated.