Hi Wade, We considered a number of approaches including just deleting oldest snapshots first and progressing through to the newest snapshots. When you consider the default snapshot schedules we are going to use, the model is that snapshots get thinned out over time. So in situations were disk space runs low, we stay consistent with this model but accelerate the aging process and thin out snapshots quicker, instead of just chopping the end off. The exception to this is that frequent snapshots will only get deleted as a very last resort. The reason for this is that frequent snapshots typically consume very little space, and they will get deleted within an hour or so anyway. And more importantly, the most common type of error is human error rather than hardware failure, such as accidentally deleting or overwriting a file or corrupting it. These kind of errors are usually noticed instantly or very soon after the event so retaining the frequent snapshots will hopefully provide some reasonable protection against this most common type of error.
Cheers, Niall. -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
