I am considering purchasing a PowerEdge 2650, 2x2.8GHz, 4GB RAM, with five 73 GB SCSI 320 HDDs, and I want to configure it as RAID 10 with four disks, having one hot spare. I am going to request a PERC4-DC RAID controller (LSI card, dual channels, 320MB/sec, 128 MB cache) instead of the standard PERC3-Di which is an Adaptec 160 controller that has a bad reputation for performance.
However, I am unsure if the PERC4-DC controller supports RAID 10 proper, or just RAID Level 1-Concatenated like the PERC4-Di spec says at http://docs.us.dell.com/docs/software/smarrman/marb32/ch8_perc.htm (you may have to log in to access that page). Specifically, it says, "RAID 10 support on [the PERC4-Di] controller is implemented as RAID Level 1-Concatenated." Since the PERC4-Di is the integrated/onboard version of the PERC4-DC, I suspect that its RAID support is the same. Does anyone know the details on this or where it is documented?
If I opted for software RAID instead, I think hot swapping would be more trouble, but would Dell's RAID monitoring still work full-featured? Are there other drawbacks to running software RAID vs hardware RAID with the PERC3/PERC4 controllers?
Also, the server has an option for a 5 Bay (2+3) hot plug SCSI split backplane. As I recall, channels are transparent to the RAID array so using a split backplane with a four disk RAID 10 configuration should be fine. Is this correct? Will the hot spare be available to both channels in the event of a disk crash?