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RAID in disk virtualization in Perc controller.

I was watching video tutorial for configuring Dell T410 server, The guy shows he configures virtual RAID through configuration.

The server has 4 disks and creates virtual RAIDs. Does the virtual RAID actually show equal performance of what physical RAID configuration can do? Depending on┬┐ choice of RAID, the physical disk's spindle and needle move as what physical RAID does?

 What if three different virtual RAIDs are configured, RAID 1, 0, 5. How spindle and needle move to satisfy all three different RAIDs?
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crcsupport
Asked:
crcsupport
2 Solutions
 
PowerEdgeTechIT ConsultantCommented:
What do you mean by "virtual RAID"?  Do you mean a Virtual Disk?  That is just another name for a RAID array.  And what controller are we talking about?
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DavidCommented:
Just take the virtualization out of the equation.   Performance is a function of the amount of work it is told to do.  The RAID controller has no idea if requests are coming from multiple virtual machines, or a single LINUX host, or any other O/S.   The RAID layout, whether you are using host-based RAID or a RAID controller provides different performance characteristics for each type of I/O, as well as RAID levels.
 
The relative performance characteristics of RAID0,1,5 are just done to death online. As well as how each RAID level works. There are lots of articles.    

It is possible that one can configure a dozen or more different RAID levels all at the same time on the same disks, but not if the PERC is doing the RAID. You have to let the O/S do the RAID.  LINUX does this quite well.

The RAID stack figures it out, and the disks do what they are told.  If you want to know how this works, then unless you want to look at some source code then suffice to say, that the RAID software balances I/O as best as it can using some rather sophisticated load balancing algorithms.
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crcsupportAuthor Commented:
PowerEdge,
You're correct. It was regular raid configuration, virtual disk. I think I spent too much on virtualization, anything says 'virtual' i get high.
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