Re: [MeeGo-dev] File system development pondering
On Mon, Jul 19, 2010 at 15:07, Gary Birkett liq...@gmail.com wrote: It has been pondered to incorporate some smart unionfs layering onto the main filesystem of meeog/maemo. The layering should be able to know there is a smaller (256/512 MiB) fast layer, with a much larger and potentially slower storage layer ontop. I am aware btrfs supports subvolumes, but do not think this is quite what is required) Although it's at a block, rather than file, level; perhaps the work on bcache could be useful? Instead of using just memory to cache hard drives, he proposes to use one or more solid-state storage devices (SSDs) to cache block data (hence bcache, a block device cache). -- http://lwn.net/Articles/394672/ Presumably there's no reason the same code and approach couldn't be used to cache slow flash on fast flash. Cheers, Andrew -- Andrew Flegg -- mailto:and...@bleb.org | http://www.bleb.org/ Maemo Community Council chair ___ MeeGo-dev mailing list MeeGo-dev@meego.com http://lists.meego.com/listinfo/meego-dev
[MeeGo-dev] File system development pondering
Hi, This started as a discussion in #maemo yesterday, but is just as relevant here. I have looked at btrfs (https://btrfs.wiki.kernel.org/index.php/Main_Page) and whilst it incorporates a lot of features cannot determine whether the following is generically supported: It has been pondered to incorporate some smart unionfs layering onto the main filesystem of meeog/maemo. The layering should be able to know there is a smaller (256/512 MiB) fast layer, with a much larger and potentially slower storage layer ontop. I am aware btrfs supports subvolumes, but do not think this is quite what is required) Most of the devices we are currently targeting will have this kind of space/speed problem where the smaller faster layer will currently exist and outperform the large storage. The aim would be to monitor filesystem usage and as requirements change to automatically move the most used components into the fast area whilst moving the least used back to the slower area. In principle, it is fairly simple to understand, though I am told that in practice it would be a complex and challenging task to undertake. Hence, I am here asking the experts - would such a thing be feasible, has it already been done (in btrfs perhaps) and if so is it usable in meego/maemo ? This is of course just a starting point for extra discussion. thanks in advance Gary ___ MeeGo-dev mailing list MeeGo-dev@meego.com http://lists.meego.com/listinfo/meego-dev
