Kyle McDonald wrote: > Bill Sommerfeld wrote: >> On Wed, 2008-02-27 at 13:43 -0500, Kyle McDonald wrote: >> >>> How was it MVFS could do this without any changes to the shells or any >>> other programs? >>> >>> I ClearCase could 'grep FOO /dir1/dir2/file@@/main/*' to see which >>> version of 'file' added FOO. >>> (I think @@ was the special hidden key. It might have been something >>> else though.) >>> >> When I last used clearcase (on the order of 12 years ago) foo@@/ only >> worked within clearcase mvfs filesystems. >> >> It behaved as if the filesystem created a "foo@@" virtual directory for >> each real "foo" directory entry, but then filtered those names out of >> directory listings. >> >> Doing the same as an alternate "view" on snapshot space would be a >> simple matter of programming within ZFS, though the magic token/suffix >> to get you into version/snapshot space would likely not be POSIX >> compliant.. >> > Ahh. > > I suspected it should be 'possible' to code it into ZFS. > > The reason it's been left to runat instead seems to be POSIX compliance > then?
Yes, we have runat for POSIX compliance. An earlier prototype of Solaris extended attributes utilized a /@/ syntax to enter enter xattr space. For example: /data/file1/@/ /data/file1/@/attr.1 ... or /data/dir1/@/ A readdir of /data/dir1 wouldn't show the @ directory, but you could always request to enter it. This violated posix in a couple of ways. One we took away the @ filename and two you can't have a directory on a file. It was a really nice model, and I still kind of wish we could have integrated it that way. -Mark _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
