On Tue, 28 May 2002, [iso-8859-1] Jakob Østergaard wrote: > Either it reconstructs it "right" or it does it "wrong". It seems in > his case it did it right. Lucky him. > > Hoever, the persistent superblocks will overwrite the last few KB of his > *filesystem* on each partition. So things *may* seem to work, but the > system will fail horribly later. After an fsck the RAID suprblocks will > be damaged. After another mkraid the filesystem will be damaged again. You should be able to pre-plan by creating initial ext2 file systems that are smaller than the partition size. You can do this by specifying the number of blocks in the file system when you run mke2fs. mke2fs [options] device blocks You should be able to calculate the eventual location of the md superblock and select an appropriate block size for each partition to insure that the superlbock and the filesystem do not overlap. Even if you've had sucess thus far, it's likely that problems will arise as the filesystem fills up-- when the last blocks are allocated, and they overlap the md superblock. This probably isn't worth the effort unless you are doing multiple installs with the same partition layout and hardware, but it seems that it might be the case here. I think the formula should be something like: blocks - (blocks % 64) - 64 = md offset That's for 1k blocks... ( like from fdisk -l) I'm a bit lazy to double check, but I think that formula works. Then when creating a filesystem divide by block size and create a file system that's the right size... --- Derek Vadala, derek@cynicism.com, http://www.cynicism.com/~derek - 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
