RE: Where do I learn about SAN backup?

Joe said:

Okay, this is making some more sense.

When you IPL the flash copy LPAR, everything is just a pointer to the existing production LPAR (until it changes). <--- correct

If you didn't change a single block of data on production, you'd in effect have nothing but
pointers to that data. Until you changed something on the flashed partition. <--- Correct, as long as nothing changes the live data

So you have:

Data that has not been changed on either partition <-- this data lives in the live partition
Original version of data that has since been changed on production <-- this is copied to the Flash partition
Data that has been changed on the copy partition <--- copied from live to flash before it is changed on the flash partition

And some serious magic that keeps it all in order. <--- it's all in that bitmap and a couple of simple rules!

So it would seem that you have to be careful not to touch your production data
in the flash copy partition until after you back it up. <--- but usually only the jobs backing up the data run in the flash partition!

If you for example cleared a master file [IN THE FLASH PARTITION] and then backed it up on the flash copy, my guess would be it would be as if you cleared it on production and backed it up. <--- correct

If you for example cleared a master file [IN THE LIVE PARTITION AFTER YOU MADE THE FLASH COPY]
and then backed it up on the flash copy, <-- you'd still have a complete copy of the data!

But even so, that's pretty fantastic stuff.