* Joakim Tjernlund <[email protected]> [120124 02:18]: > Ed W <[email protected]> wrote on 2012/01/23 19:43:49: [ .. ] > > I'm doing something like this using aufs. The performance seems "not > > bad", but you get a couple MB or so memory hit. (I'm using squashfs as > > well, so unsure which causes the main memory increase). > > hmm, not sure how aufs would work out. One would like to permanently delete > the
aufs is A Union FileSystem. You can have a RO "branch" (say SquashFS) and a r/w "branch" (say JFFS2 or UBIFS.) When you write it will write to the r/w branch and when you read it will read from the r/w branch if it exists, else the r/o. So, if you want to permanently delete the old software. Write it to the filesystem r/w filesystem (initially or after you have the aufs mounts mounted.) Then you can delete from the r/w filesystem and it's gone for good. > old sw at some point and I don't see how, perhaps I misunderstand something? > > How does aufs do w.r.t power cuts? We need a reliable FS w.r.t power cuts. In > the > past we have used JFFS2 on NOR flash and that has worked really well. Now > we need to switch to NAND due to size requirements. You still want to pick a r/w branch with a filesystem that handles power cuts well. You can continue to use JFFS2. [..] Todd
