On 11/26/06, Akhilesh Mritunjai <[EMAIL PROTECTED]> wrote:
I'll recommend going over the zfs presentation. One of the points they listed was that - even in case of silent errors (like you noticed) other systems just go on. Your data gets silently corrupted and you'd never notice it. If there are few bit flips in jpegs and movie files, it will almost never be noticeable. However, there are places where it will cause catastrophy but in day-to-day cases we don't come across or even if we do - we attribute them to $CAUSE, forget and go on. ZFS tries to fix this problem as one of its core goals. (that is why block checksums are there).
The fact that ZFS will detect and report errors that other systems silently gloss over is fairly well documented at this point, and it's a big win for ZFS, and part of my motivation for running it. However, what you say about bit flips in jpegs, at least, is misleading. If you never open the file you won't notice -- but that's true for *any* file, of course! If you *do* open the file, everything after the flipped bit will be drastically altered, or completely unreadable. I've viewed a number of damaged jpegs, and the visible consequences are always really drastic. Now, in an uncompressed TIFF file, it'd be mostly invisible, because it would affect only one pixel. The issue is that jpeg is a heavily compressed format; the next data always depends on the previous data, so everything after an error is changed. -- David Dyer-Bennet, <mailto:[EMAIL PROTECTED]>, <http://www.dd-b.net/dd-b/> RKBA: <http://www.dd-b.net/carry/> Pics: <http://www.dd-b.net/dd-b/SnapshotAlbum/> Dragaera/Steven Brust: <http://dragaera.info/> _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
