-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 17/07/13 14:24, Florian Lindner wrote: > metadata ist mirrored on each device, data chunks are scattered more or > less randomly on one disk. > > a) If one disk fails, is there any chance of data recovery? b) If not, > is there any advantage over a raid0 configuration. I was using that exact configuration when one disk failed (2 x 2TB Seagate drives). The data was backed up in multiple ways, a lot of it was in source control systems and the remainder was generated information. Essentially the risk was worth taking since nothing would be lost. One drive gave up mechanically - the controller still worked and it was fun running SMART tests and having huge amounts of red text show up in response. The initial symptoms were that various programs crashed or didn't launch with no diagnostics. That is typical behaviour for Linux apps when they get I/O errors on reads and writes. Eventually I figured out the problem, and bought a new 4TB drive to replace both originals and started recovery. Out of ~750GB of original data I could recover just over 2GB which represented files whose entire contents were on the unfailed drive. Having the metadata duplicated was however immensely helpful and I could easily get a list of all directories and filenames, and used that to guide what data I recovered/regenerated/reinstalled/checked out. Meanwhile the performance improvement by having the data scattered across both drives was noticeable. I would often see it in iostat roughly evenly balanced. Roger -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlHnTDgACgkQmOOfHg372QSTJwCeI17B4QhstkM4nnO0qOMDB1ae WfwAoOBu6lBwZ+GyFwnZVGXC5ki7Oge/ =i+YN -----END PGP SIGNATURE----- -- 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
