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Should I use RAID 1 or RAID 5 for my Virtual Machine host server (Microsoft Hyper-V)?

I am building a server that will be used as a virtual machine hosting server, using Microsoft Hyper-V as the virtual server hosting OS. The hardware I am using will be a motherboard with capacity for 6 SATA 10,000 RPM disks. I can set them up using RAID 1 or RAID 5. I cannot use a mix of different RAID options for the disks. I must choose either RAID 1 or RAID 5 for all the disks. Which option would be best for performance? I plan to create 10 virtual machines on the system. I know I would have more total disk capacity using RAID 5 instead of RAID 1 (mirroring), but am wondering if there is a benefit to using RAID 1 for the entire system, in regards to general performance. The virtual machines will be a mix of workstations, database servers, web servers, and other systems. The host OS (MS Hyper-V) uses a very small amount of disk space. The a majority of space will be dedicated the various virtual servers running. There is no need to send me links to websites describing RAID (I know about the various general benefits of the different types of RAID). I am interested in hearing from someone who has implemented a RAID configuration when setting up a virtual hosting server and have some good advice regarding which option offers best performance.

Public Comments

1. RAID 5 may provide more performance than RAID 1 RAID 1 is mirroring only. RAID 5's striping should outperform RAID 1 However, you may be better off investigating a hardware RAID card than trying to build a software RAID from the motherboard sockets. Your gains from RAIDing may be offset by processor overhead. Also, I wouldn't be surprised if 6 x 7200 RPM drives with high areal density (320 GB platters) and a hardware RAID card outperformed or at least equalled 6 x Velociraptors for a comparable price. See www.storagereview.com for comprehensive comparisons of performance.