On Fri, Mar 29, 2013 at 4:09 PM, Daniel Hilst <danielhilst@xxxxxxxxx> wrote: > Suppose that I have two big filesystems, dest fs and source fs.. I want > to copy whole source fs to dest fs, but I need to keep > source filesystem online I can't mount source fs read only and copy.. > > The idea is, mount both filesystems "together", and make write/read > operations go on this way > Read operations: > 1. See if data is already on dest fs, > 2. If is then read data and bright back to caller (lets call this > cold read) > 3. If is not, then read file from source fs, put it on page cache, > and change the backstorage of that page.. > 3.1 So when this page get dirty or too old, it will be writed to > dest fs > > The problem here is, I need to remap every data and metadata on > step 3 (inodes and stuff), I think that read only data, isn't writed to > disk, > so in case of old page, this page would be freed from memory and > not write to dest fs.. so I need read only pages to be forced dirty.. > > Write operations: > 1. Write data to dest fs > 2. Mark data as present on dest fs > > > Also I need to know when copy is finished, so I need a tool to > crosscheck both filesystems and say what was copied and what wasn't, and > give me some percent of remaining unsynced data. When I get 100% of data > in sync I can umount source filesystem and use its storage for other > propose. > > The go here is move data online, where I can't bring data offline.. > > I'm a kernel newbie, I have just read a lot about page cache and VSF, > but this seems possible, right? Are you looking for a pre-existing solution? Or you want to write something? Greg _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
