Is there anything going on in this area? We have btrfs in RAID10 using 4 HDD's for many years now with a rotating scheme of snapshots for easy backup. <10% files (bytes) change between oldest snapshot and the current state.
However, the filesystem seems to become very slow, probably due to the RAID10 and the snapshots. It would be fantastic if we could just add 4 SSD's to the pool and btrfs would just magically prefer to put often accessed files there and move older or less popular files to the HDD's. In my simple mind this can not be done easily using bcache as that would require completely rebuilding the file system on top of bcache (can not just add a few SSD's to the pool), while implementing a cache inside btrfs is probably a complex thing with lots of overhead. Simply telling the allocator to prefer new files to go to the ssd and move away unpopular stuff to hdd during balance should do the trick, or am I wrong? Are none of the big users looking into this? Ferry -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
