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005.l1D05rpF034888@apollo.backplane.com> <20070213005941.GD68703@dmr.ath.cx>
From: Matthew Dillon <dillon@apollo.backplane.com>
Subject: Re: Plans for 1.8+ (2.0?)
Date: Mon, 12 Feb 2007 17:35:25 -0800 (PST)
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:With the infinite snapshots scheme, how does one reclaim space?

     You reclaim space by destroying the oldest (deleted) data, and
     by collapsing snapshots (that is, collapsing time ranges).

     So for example, under normal filesystem operation if a filesystem
     sync occurs every 30 seconds, then you have about a 30 second 
     snapshot.

     Lets say that within the period of an hour you make several edits to
     a file.  You would probably have a snapshot of every edit you made
     to that file.

     But then if you have a cron job that runs, say, once a day, and
     collapses all snapshots to a one-hour granularity, then after that
     run you would only have a snapshot of your file as it was at the top of
     each hour.

					-Matt
					Matthew Dillon 
					<dillon@backplane.com>