[linux-lvm] Mirroring

[Mats Wichmann]

At 01:18 AM 02/12/2000 +0100, Heinz Mauelshagen wrote:
>> Hi, I am relatively new to this list, and to Linux LVM, but when Heinz was
>> at the U of MN last month, I asked this very question, and Heinz's
>> response was that there are not currently plans for mirroring LEs to PEs
>> precisely because this functionality is provided by md or RAID hardware.
>
>Yes.
>The LVM covers the dynamic allocation of storage.
>Either RAID soft- or hardware covers the redundancy.
>
>IMO you get a much simpler systemarchitecture this way which is much
>more reliable for day to day production.
>
>IOW: it saves your money.

perhaps...but it makes it impossible, if I've understood this
architecture, to use a floating mirror for live backups.

i.e., set up 3 10 gb partitions "a" "b" and "c", and one 10 gb spare "d"

attach "d" as a mirror of "a", wait for sync, detach, backup "d"
attach "d" as a mirror of "b", wait for sync, detach, backup "d"
etc.

(for redundant situations, "a" "b" and "c" may already be mirrored
so you're attaching the floater as an _additional_ mirror)

maybe the application for such usage is not widespread enough, though...