On 08/30/2014 02:37 PM, Patrick Goetz wrote:On 8/30/2014 10:10 AM, Simon Matter wrote:I suggest -aH to preserve single instance storage in the backup.Does cyrus use a lot of hard links? I use rsync a lot to create snapshot backups, and use hard links across snapshots to preserve space; however, for a single instance backup and unless the filesystem includes hard links (not normal), then the -H won't do much for you. Cyrus uses hard links among copies of the same message in different mailboxes, when "singleinstancestore: 1" is set, which is the default. From the man page imapd.conf(5): If enabled, imapd, lmtpd and nntpd attempt to only write one copy of a message per partition and create hard links, resulting in a potentially large disk savings. Of course one should always use -a. The biggest concern I have about backing up mail spools is keeping the index and message stores in sync while the backup is taking place. A long time ago someone suggested using cyrdump, but when I looked into this, I couldn't find any documentation whatsoever. Is cyrdump a real thing, or did I imagine all this? Are you thinking of ctl_mboxlist? It allows one to dump the mailboxes database to a flat file. In an out-of-the-box Cyrus installation the indexes are stored with the messages in the mailbox hierarchy. If you decide to store meta-data separately, you should simply snapshot that at the same time you snapshot your mailstore. At the beginning of this thread, Marcus Schopen wrote this example: One could simply include any meta-data volumes in the snapshotting process.ctl_cyrusdb -c ctl_mboxlist -d > mailboxes.db.dump stop cyrus lvm snaps start cyrus rsync /var/lib/cyrus/ and /var/spool/cyrus to backup host remove snaps Cheers, -nic ---- Cyrus Home Page: http://www.cyrusimap.org/ List Archives/Info: http://lists.andrew.cmu.edu/pipermail/info-cyrus/ To Unsubscribe: https://lists.andrew.cmu.edu/mailman/listinfo/info-cyrus -- Nic Bernstein nic@xxxxxxxxxxx Onlight llc. www.onlight.com 219 N. Milwaukee St., Ste. 2A v. 414.272.4477 Milwaukee, Wisconsin 53202 f. 414.290.0335 |
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