This is actually the continuation my previous update on the server. As I noted in that previous post setting up a RAID 5 with six 146 GB drives and two 72 GB drives was very stupid. But I never explained why this is a stupid idea on my first post. Today we will look at the best way to mix and match different types of harddrives on a RAID system for optimum performance and the highest storage output.

The the RAID 5 system works by taking all the hard drives with even different sizes and strip the data on all of them to provide one drive fail backup support for the system. In other words, on a RAID 5 system, you an tolerate one drive failure without loosing data. In this method, the RAID controller will take the lowest capacity of all the drives on the array and multiply that lowest capacity by the number for drives regardless of the capacities of the larger drives. For example, if we have two 72 GB drives and six 146 GB drives, the RAID controller will see all the eight drives as 72 GB drives. By doing the math for the RAID 5 system: (72 GB * 8)-72GB = 567 GB in total. Considering 146 GB *6 itself is 876 GB, this creates a a lot of wasted space. In addition to this reduced space, the 72 GB HDs are running at 15K RPM while the 146 GB HDs are running at 10 K causing the RAID to operate at the lowest RPM value of 10 K even with the six 15 K drives have the capability to Continue reading Server RAID rebuilt… →

Yesterday I had to rebuild my entire server because I made an error in how I created the RIAD system. When I initially setup the server, I placed all my 146 GB and 76 GB units of harddrives in one RAID 5 cause a huge loss of data space. When you add different sizes of HDs to a RAID 5 array, the controller takes the multiples of the smallest and the slowest RPM for the maximum output causing a huge limitation on the RAID. I dismount the entire RAID 5 and mounted the 146 GB at 10 K on RAID 5 and an independent RAID 1 for the two 76 GB units at 15 K. Then I installed the OS in the 76 GB faster drives giving me a faster boot time while the six 146 GB on RAID 5 provided a maximum yield of storage space.

This is the best configuration for the hardware I have right now.  Unless I upgrade the 76 GB units with new 146 GB units which I don’t think I will go for right now. Let’s compare what I had previously to what I have now in my next post!!