On Mon, 27 Apr 2009 18:25:42 -0700, Richard Elling <richard.ell...@gmail.com> wrote:
>The concern with large drives is unrecoverable reads during resilvering. >One contributor to this is superparamagnetic decay, where the bits are >lost over time as the medium tries to revert to a more steady state. >To some extent, periodic scrubs will help repair these while the disks >are otherwise still good. At least one study found that this can occur >even when scrubs are done, so there is an open research opportunity >to determine the risk and recommend scrubbing intervals. Some high availablility storage systems overcome this decay by not just reading, but also writing all blocks during a scrub. In those systems, scrubbing is done semi-continously in the background, not on user/admin demand. -- ( Kees Nuyt ) c[_] _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
