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-   -   Move from ATA RAID to native RAID (https://www.linuxquestions.org/questions/linux-hardware-18/move-from-ata-raid-to-native-raid-146292/)

Nalfeshnee 02-15-2004 05:54 AM

Move from ATA RAID to native RAID
 
Hi, I have been playing with RAID on Linux for a while now, and have had some success with the ataraid variety, but would now like to move to using Linux's native RAID (non-ATA, md-flavour).

Quick hardware check:

MSI KT3 Ultra2 Motherboard with Promise 20276 on-board RAID, 2 x 30GB Disks as ATA RAID 1 (Mirror). Normal IDE has 10Gb /dev/hda, and CDRW on /dev/hdc (using ide-scsi).

According to the famous 'murty' RAID HOWTO (search on Google for '+murty +RAID': I can't post the URL here since I don't have 5 posts yet *G) it is possible to use the Promise controller as a vanilla IDE controller, simply by ignoring the RAID which is present as /dev/ataraid/d0 and accessing drives /dev/hde and /dev/hdg directly.

Before I go and do this -- after backing-up everything I can think of -- I just wanted to ask if anyone has any experience of doing this, since I didn't find the murty HOWTO very clear on this point. My questions:

-- OK, one 'ignores' the RAID, but what does this mean as regards BIOS and the Fasttrak Setup screen? Does one disable RAID there, or just leave the BIOS thinking that it's doing a RAID 1 when in fact it isn't? If one has to turn the RAID 'off' how does that happen -- and what should one do beforehand?
-- I assume that one couples the partitions under some sort of RAID 1 using the md* tools. I've done this before as part of server setup, so no questions there, but I wondered if there are any special steps to take here. I am of course not instaling anything fresh here: I will have a /dev/hde which I need to mirror onto /dev/hdg and not have the luxury of making mistakes! It shouldn't be too difficult -- I mean, the partitions are exactly the same at the moment anyway -- but one never knows.

Any ideas or info appreciated. If I get no information, then I'll go ahead and let you know how it works :D


Ed

Nalfeshnee 02-16-2004 07:46 AM

Oh, and also...
 
I know, replying to my own thread!

Anyways, I was ALSO wondering if the following is possible:

Can one use *four* disks on the Promise controller -- there shouldn't be any reason why not..?

This would be very good for a cheap IDE RAID 5 (3 active, 1 spare) -- or is it a stupid idea because slave IDEs are not good for RAID?

Thanks!


Ed


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