On Mon, 2008-07-21 at 10:40 +0300, Ahmed Kamal 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 >
Btrfs already has a raid level where things are duplicated on the single spindles and it is on by default for metadata. mkfs isn't currently setup to use this on data blocks, but it is certainly possible (look for BTRFS_BLOCK_GROUP_DUP). This is definitely less reliable than two physical devices, and I worry that such a feature would give people the impression that single drive raid is a good idea. As others have already said, the drives to have considerable error detection and correction already. One of the main benefits of the checksums is being able to tell which copy of the data from a group of drives is correct. In terms of detecting errors, the data checksums will do that. -chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
