As long as you can catch up to a point where you read all busy pages and none were written in the meantime, yes. Generally, the way VM migrations deal with thi

As long as you can catch up to a point where you read all busy pages and none were written in the meantime, yes. Generally, the way VM migrations deal with this is by suspending the VM once a small enough set of dirty pages remain. I think the same can be done with block devices on Linux; if I remember correctly, there's some file in sysfs that you can poke to quiesce a block device. Just make sure your app is fully in RAM/cache, ideally locked, if you do this to your root filesystem :)