On Tue, Sep 16, 2008 at 01:28, Ben Rockwood <[EMAIL PROTECTED]> wrote: > This is wrong... Ditto blocks are exactly what the name suggests, > duplicate data blocks. If you write 8KB and "copies=2" 16KB is written > to disk. But by default copies=1, and only one block is written.
> The primary purpose of ditto blocks is to provide data redundancy when > you do posses multiple disks, for instance on a laptop drive. If one "do not"? > block becomes corrupt, ditto blocks can provide a duplicate block to > prevent data loss. Yes, but my understanding is that this isn't a very good method of providing redundancy; AIUI the two copies aren't guaranteed to be on different disks, so if that disk dies you've lost all the copies of that file. Not to mention the pool won't be importable with a missing disk. > Ditto blocks are NOT just for metadata. True... but they aren't on (for all data) by default. You're right that ditto blocks can be used to make multiple copies of data, but I think they're a bad strategy for most situations. Will _______________________________________________ storage-discuss mailing list [email protected] http://mail.opensolaris.org/mailman/listinfo/storage-discuss
