When you say 'a faster way', are you trying to move the data from one SAN to another, so that you can detach the original and you need to make the offline time as short as possible?
If your disk is LVM, then you might be better to proceed like this:-
- Get the new LUN assigned and re-scan to pick it up if necessary
- Make the whole new LUN into an LVM Physical Volume with pvcreate
- Add the PV into the volume group containing the data you want to move
- Alter the logical volume holding your filesystem/data to have two copies, specifying the new PV as the target. This will take a long time, but the applications remain available because the data is still accessible.
- Verify that the logical volume has no errors reported.
- Alter the logical volume to have just a single copy, specifying the old SAN device to be removed
- Repeat the mirror/drop for as many logical volumes as you need to move to completely free the old PV
- Remove the old PV from the volume group
- Detach the old LUN from the OS
- Detach the old LUN from the SAN side
Using the tools in the OS rather than trying to do the work yourself should be a lot neater. The logical volume is moved, but the filesystem has no idea about it, so all the files remain exactly as they were and your applications, backups or whatever can happily carry on.
I prefer to add a mirror to the new device rather than just execute a move for large logical volumes just in case there are any issues in the process. You don't destroy the original so you can always drop the new copy and start again.
Have I missed the point and waffled on about something irrelevant? My apologies if I have, but I hope that this helps. If you are looking to make another copy to be used separately, then we might be able to use LVM to do that too, but that would be a copy at a fixed point in time that would then go out of date with respect to the original as either is changed (you suggest that there are many concurrent processes working on it)
Anyway, I hope that this helps. Please feel free to correct me if I'm way off target.
Kind regards,
Robin