An experiment of applying RS codes for protecting data, worth a look http://ttsiodras.googlepages.com/rsbep.html He overwrites a series of 127 sectors and still manages to correctly recover his data. We all know disks give us unreadable sectors every now and then, so at least on workstations/laptops this could really be useful ? Advantage over single-disk-raid1 is storage efficiency (4.2MB becomes 5.2MB), that means we get 80% of useable disk space, instead of 50% if I decide to raid1 everything ? On Mon, Jul 21, 2008 at 6:03 PM, Dongjun Shin <djshin90@xxxxxxxxx> wrote: > On Mon, Jul 21, 2008 at 4:40 PM, Ahmed Kamal > <email.ahmedkamal@xxxxxxxxxxxxxx> wrote: >> I definitely hope btrfs has this per-object "copies" property too. >> However, simply replicating the whole contents of a directory, wastes >> too much disk space, as opposed to RS codes >> > > Although adding redundancy mechanism will help increasing the integrity of data, > I'm not sure whether repeating the same kind of mechanism twice will help. > (AFAIK, RS is common in HDD and BCH is common in flash due to their own > physical characteristics) > > I think it is better to have another redundancy mechanism (like RAID1) > which is independent of the algorithm used by the underlying storage. > > -- > Dongjun > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
