I am a programmer, I studied about software, hardware and Fake raid's and I am unable to understand how fake raid communicates with operating system (Linux)? I mean which software layer or driver involved in this?
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Can you clarify what exactly is Fake RAID? – Alexander Dzyoba Feb 25 '14 at 12:48
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@avd see http://skrypuch.com/raid/ – Chinna Feb 25 '14 at 13:35
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Fake RAID is created by motherboard by formatting disks and storing Fake RAID metadata on it.
There is a special tool by Red Hat - dmraid(source). It's a some kind of bridge between Fake RAID and Linux device-mapper dm-raid target. Yes, it's confusing, don't mess dmraid and dm-raid. dmraid is utility, dm-raid is one of device-mapper targets.
dmraid tool scans all block devices and looks for Fake RAID metadata. After detecting Fake RAIDs it create corresponding device-mapper devices. For example, if there was Fake RAID0 then dmraid will create mapped device with striped target (dm-stripe.c). If there was Fake RAID1, then it will create mapped device with raid target (dm-raid.c).
So, the answer is: Fake RAID communicates with Linux through device-mapper. There are several drivers involved in this (dm-stripe, dm-raid) and useful utility dmraid.
Alexander Dzyoba
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