On 11/03/2012 09:40 AM, V G wrote: > No, BTRFS is copy-on-write to some other part of the filesystem. > > > On Fri, Nov 2, 2012 at 10:21 AM, Darron Black wrote: > >> With modern filesystems, writes are >> always going on at the same file structure portion of the disk... so >> many writes are going to cause a wear level operation and swap with some >> other random part of the drive. >> BTRFS appears to still be marked unstable. It's tomorrow's modern. :) I should have added a "most" in there. In any case, the wear levelling will still happen and the same problem=20 exists... there is no way to identify or control what parts of an SD=20 card are going to be erased beforehand. They completely break any kind=20 of journalling or high reliability mechanisms that I know of. Only the internal SD card's controller implementation can solve this=20 problem, and I doubt many do. With supposedly fault tolerant SD cards,=20 you have to trust the manufacturer to do it right (which is not easy). Darron Black --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .