Toby Bluhm wrote: > Ruslan Sivak wrote: >> Feizhou wrote: >>> Ruslan Sivak wrote: >>>> Feizhou wrote: >>>>> >>>>>> I do have a SIL3114 chipset, and I think it's supposed to be >>>>>> supported by device mapper. When I go to rescue mode, I see it >>>>>> loading the driver for SIL3112, but nothing appears under >>>>>> /dev/mapper except control. Are there instructions somewhere on >>>>>> getting it to use my controller's raid? >>>>> >>>>> Your controller only has a bios chip. It has no raid processing >>>>> capability at all. >>>>> >>>>> You need to use mdadm. anaconda should be able to let you create >>>>> to mirrors and then create a third array that stripes those md >>>>> devices, >>>>> _______________________________________________ >>>> Anaconda doesn't let me create a stripe raid set on top of a mirror >>>> set. And it doesn't detect it when I do it manually. >>>> Also the bios chip presents additional issues. I believe when I >>>> don't have a raid array set up, it won't boot at all. When I have >>>> it on raid10, I had trouble booting, and when I have it on >>>> concatenation, everything works fine, until a drive is replaced. >>>> At that point, i have to recreate the array, as concatenation is >>>> not a fault tolerant set, and at this point I seem to lose all my >>>> data. >>> >>> It won't boot at all without a raid array setup? That sounds really >>> funny. >>> >> Actually I'm not 100% sure on this, but I think this is the case. I >> believe the first time I set it up as a raid10, assuming that linux >> will just ignore it. I installed centos by putting boot on a raid1, >> and root on LVM over 2 raid1 sets. I had trouble getting it to boot. >>>> Is there a way to get it to use the raid that's part of the bios >>>> chip? >>> >>> Repeat after me. There is no raid that is part of the bios chip. It >>> is just a simple table. >> Yes, I know this is fakeraid, aka softraid, but I was hoping that >> using the drivers would make it easier to support raid 10 then with >> mdadm, which seems to be impossible to get to work with the >> installer. I'm not even sure why the raid10 personality is not >> loaded, as it seems to have been part of the mdadm since version 1.7. >>>> Something about device mapper? >>> >>> >>> You need the fake raid driver dmraid if you are going to set up >>> stuff in the bios. What version of centos are you trying to install? >>> libata in Centos 5 should support this without having to resort to >>> the ide drivers. >>> _________________________________ >> I'm trying to install centos 5 - the latest. How would I go about >> using dmraid and/or libata? The installer picks up the drives as >> individual drives. There is a drive on the silicon image website, >> but it's for RHEL4, and I couldn't get it to work. I'm open to using >> md for raid, or even LVM, if it supports it. I just want to be able >> to use raid10, as I can't trust raid5 anymore. >> > > IIRC you had two out of four new disks die? So maybe it would be more > accurate to say it's your hardware you don't trust. Raid5 is used > without problems by ( I assume ) many, many people, myself included. > You could have a raid10 and still lose the whole array if two disks > that in the same mirror die at once. I guess no software in the world > can really overcome bad hardware. That's why we do backups :) > > Anyway, perhaps excersizing /stressing the disks for a few days > without error would make you feel more confident about the HDs. > Actually, 2 disks did not die. Due to the fact that it was a new raid 5 array (or for whatever reason), it was rebuilding the array. One of the drives had a media error, and this caused the whole array to be lost. This is exactly what this article warns about: http://www.miracleas.com/BAARF/RAID5_versus_RAID10.txt Russ