--- On Mon, 4/26/10, Michael Evans <mjevans1983@xxxxxxxxx> wrote: > I don't think I've read the RAID FAQ you speak of, a link > would have been helpful. Sorry... this one, question #7: http://git.debian.org/?p=pkg-mdadm/mdadm.git;a=blob_plain;f=debian/FAQ;hb=HEAD > mdadm --create ... --layout=(man mdadm) blockdev0 blockdev1 > blockdev2 blockdev3 > > n2 == Creates almost the behavior you described; each > stripe consists > of b0c0 b0c1 b1c0 b1c1 (blockXcopyY) > o2 == Data backup is in the next stripe: that is mirrored > and rotated > stripes: b0c0 b1c0 b2c0 b3c0 // b3c1 b0c1 b1c1 b2c1 > f2 == The first half is like raid0; the second half is like > the o2 > above, but over the entire first half. > > More info on far from man 4 md > When 'far' replicas are > chosen, the multiple copies of a given > chunk are laid out quite distant from each other. > The first copy > of all data blocks will be striped > across the early part of all > drives in RAID0 fashion, and then the next copy of all > blocks will be > striped across a later section of all drives, always > ensuring that all > copies of any given block are on different drives. > > The 'far' arrangement can > give sequential read performance > equal to that of a RAID0 array, but at the cost of > reduced write > performance. Yep, I've read all that, and it tells me what happens in the trivial case when 4 drives are specified. However, it doesn't say what happens with a larger number of drives. I'm looking for the kind of control I can get with RAID 1+0, where I can specify exactly which drives are mirrors of each other. Is that possible with RAID10? Thanks. Andrew -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
