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On Seg, 2008-02-11 at 14:39 -0700, Andreas Dilger wrote:
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<FONT COLOR="#000000">The problem with ctime (on Linux as well) is that it is possible for the</FONT>
<FONT COLOR="#000000">system clock to go backward, whether due to ntp, or because the hardware</FONT>
<FONT COLOR="#000000">clock is incorrect/reset, so it cannot be depended upon to be monotonically</FONT>
<FONT COLOR="#000000">increasing for the life of the lustre filesystem.</FONT>
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Ok. In that case, we could either add a new 64-bit version field to the dnode (or znode) similar to the one in ldiskfs, or we could look at the birth time (txg nr) of all the block pointers in the dnode.<BR>
Using txg numbers might not be very useful if an object is migrated from one storage device to another, but I have not read the HSM HLD so I'm not sure if this is a problem or not.<BR>
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Cheers,<BR>
Ricardo<BR>
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<B><FONT SIZE="1">Ricardo Manuel Correia</FONT></B><BR>
<FONT SIZE="1">Lustre Engineering</FONT><BR>
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<B><FONT SIZE="1">Sun Microsystems, Inc.</FONT></B><BR>
<FONT SIZE="1">Portugal</FONT><BR>
<FONT SIZE="1">Phone +351.214134023 / x58723</FONT><BR>
<FONT SIZE="1">Mobile +351.912590825</FONT><BR>
<FONT SIZE="1">Email <A HREF="mailto:Ricardo.M.Correia@Sun.COM">Ricardo.M.Correia@Sun.COM</A></FONT>
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