[linux-lvm] writable snapshots ? (a la timefinder BCV)

[David Stes <stes pandora be>]

Hello,

There is an option --snap to the lvcreate utility to create a read-only snapshot(frozen image) of a volume.

Is there a possibility to quickly create a rw (read/write) snapshot of a logical volume ?

I'm thinking here of applications in the style of EMC Timefinder BCV's (bcv = business continuance volumes).

For example, I want to create a snapshot of a mounted volume running Informix.

The snapshot of the mounted logical volume will be inconsistent, but it appears then to contain a 'crashed' instance of Informix, and when mounting the snapshot, I'd like to replay logfiles (do a recovery on the crashed instance) for which I need read/write access to the snapshot ...

Thank you,
David Stes.