On Tuesday 19 July 2011 16:36:20 you wrote: > On Tuesday 19 July 2011 09:06:05 Michael Orlitzky wrote: > > On 07/18/2011 11:08 PM, Jeff Cranmer wrote: > > > Pardon my additional questions before taking the plunge here. > > > > > > So, given that I have three devices, /dev/sda, /dev/sdb and > > > /dev/sdc, if I run the command mdadm --assemble --scan, would this > > > find all the components and create a /dev/md0 disk without damaging > > > the contents of the original RAID array? > > > > If you've got the space and time, a backup can't hurt. Using --scan will > > make it check the config file, but right now, there's probably nothing > > > > useful in it. This looks like what you want to do to me: > > If the --scan option is not given, then only devices and identities > > listed on the command line are considered. > > > > The first device will be the array device, and the remainder will be > > examined when looking for components. > > > > but I'd figure out where that md0 is coming from (below) first. > > > > > The only item in /dev/mapper is th default 'control' entry. There > > > is > > > a /dev/md0 item already listed, but presently when I try to mount > > > it, it reports that it is unable to read the superblock. Would the > > > command above fix this? > > > > Depends. Where'd the md0 come from? You probably have something in your > > logs or dmesg, unless that device was created manually on your old > > system.> > > > Where is the config file mentioned in your e-mail, and do I need to > > > edit it first to add the three raid disks? > > > > It's /etc/mdadm.conf. You don't need it to create or use the array, but > > you'll want to run mdadm when the machine boots and the config file > > tells it what to do. Once the array is working, you can just do, > > > > mdadm --detail --scan >> /etc/mdadm.conf > > > > to populate it. I guess also check to make sure there's no default crap > > in there these days. > > mdadm? that is for linux software raid. > > He wants to use nvidia fakeraid. He needs dmraid for that. > > Build in the dmraid support. > emerge device-mapper > emerge dmraid > add device-mapper to boot runlevel > done > > If I remember correctly > > oh yeah - nvidia fakeraid is pretty fragile. You should plan to move away > from it.
addendum: just saw that mdadm >=3 should be able to handle fake raid. My bad. -- #163933
