Hi, (apologies if this was discussed before, I _did_ some research, but this one may have slipped for me...)
Looking through the current Sun ZFS Technical presentation, I found a ZFS feature that was new to me: Ditto Blocks. In search of more information, I asked Google but there seem to be no real information other than the source code on Ditto Blocks. From the Ditto Block slide, I conclude that: - ZFS blocks can have multiple copies (up to 3), even on the same disk, but preferably on multiple disks, if possible. - The uber-block has an additional 3 copies (we already knew that) - The ZFS metadata structure has 2 or more copies (that was new to me) - In the future, users will be able to ask for multiple copies of their data (wow, what a great feature for laptop users with big, but single disks!) Can someone elaborate more on ditto blocks? Perhaps that would be a great blog entry (Google didn't find anything for "site:blogs.sun.com zfs ditto blocks"). In particular: - Are regular data blocks multiplied by default if the disk isn't mirrored/ raid-z'ed and there's enough space? - What are the general rules on what blocks get multiplied how often? Best regards, Constantin -- Constantin Gonzalez Sun Microsystems GmbH, Germany Platform Technology Group, Client Solutions http://www.sun.de/ Tel.: +49 89/4 60 08-25 91 http://blogs.sun.com/constantin/ _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
