* [Chris Mason] > Excerpts from Erik Logtenberg's message of 2010-12-15 14:26:49 -0500: >> >> The use case is a filesystem used for backups, which are rsynced >> nightly, after which a new snapshot is made. After something like 45 >> days, the old snapshots are removed. I am assuming that this way, after >> 45 days all files will be compressed naturally, but this is only >> beneficial if snapshots still fully work. If instead it results in >> storing the compressed form of every file 45 times on disk, then it >> won't help much. > > Yes, you'll end up with a fully compressed and fully shared setup after > 45 days. How would that happen? Rsync only rewrites files if they have changed. If compression happens only when a file is written to, any files that were written uncompressed will remain uncompressed until they change on the source filesystem (triggering a rewrite on the backup drive). Unless there's some magic I'm missing, expiring the old snapshots from before -o compress won't really affect anything. Øystein -- Outgoing mail is certified Virus Free. ..of course, the virus would tell you the same thing.. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
