On Tuesday March 9, miquels@cistron.nl wrote: > On 2004.03.01 02:09, Neil Brown wrote: > > On Monday March 1, miquels@cistron.nl wrote: > > > > > > What do you think of that approach ? Converting from a 1 disk setup > > > to a 2-disk RAID1 setup on an existing system is something that lots > > > of people want to do, seeing that the software raid howto even has > > > a few paragraphs dedicated to it. > > > > What I am thinking of doing is allowing: > > > > md=0,1,/dev/sda > > > > to assemble a raid1 array without a superblock which uses just > > /dev/sda. ... > > Any progress on this? No, not yet. > > The right thing to do would probably be to check if the device actually has > partitions - refuse to reduce the size of the device if it doesn't have > any partitions, or if any partition overlaps with the MD superblock. > That should be easy enough I think. Certainly do-able. But I'm not sure it is completely correct. Suppose the device isn't partitioned, and has a single filesystem on it, which is smaller then the whole. Why not shrink it then? I really want some general interface to find out how much of a drive is in-use. Maybe if "bd_claim" to a parameter which said how much was being claimed..... Or maybe claimants should reducde i_size of the block device. > > But it would take changes in both userlevel tools (add --grow to mdadm) and > the kernel, right ? So in the short run, I'll be better off by booting a > Knoppix CD and running mdadm from there, I suppose. Yes, there is a bit of work to be done before you can use this approach. > > Are you interested in the patch I made to be able to initialize (but not run!) > an array on a disk that is otherwise busy (i.e. can't be bd_claim()ed) ? > Basically it just adds a SET_ARRAY_INFO_CONFONLY ioctl. I have patches for > both the kernel and mkraid, and they're pretty simple. Not really. If it just writes out a superblock, then it can be done entirely in user-space - no kernel patch should be needed. NeilBrown - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
