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Hi,
On larger systems with VMs i take a ZFS or LVM snapshot and mount it externally to "fetch" a full (incremental) filesystem backup of the mail spool and imap spool and cyrus db on a daily base. After the backup run i destroy the snapshot. The problem with this is that you can't be sure the data on disk is in sync. Depending on how heavy the load is during the "backup" (+ your luck), you may find unpleasant surprises when you have to restore it. And you'd only know that the backup is corrupted when you try to restore it. Beside this and depending from your needs you may take a look at cyrus replication features to build a "backup" or just use standard filesystem backup tools like tar, dumpfs etc. The replication is reasonable only if you have more than one server in your deployment (and both servers with the same level of security, if not you risk to compromise the user data) or "spool size/available disk space" is low, otherwise you'd need to dedicate 2 times more space than needed to store user data, only to take a periodic backup (+ the space needed to store the backup itself). I suggest you take a look at this issue: https://github.com/cyrusimap/cyrus-imapd/issues/1763, where backups for small deployments were already discussed in detail. Though, no idea if there are plans to implement it. Answering the OP's question, I'm using Cyrus for 4 years now and I don't know about any reliable and reasonable strategy for backups of Cyrus data in SME environments. Summing it up:
Regards, Anatoli From:
Niels Dettenbach Via Info-cyrus
Sent: Wednesday, May 09, 2018 06:42 To: Info-cyrus Subject: Re: Backup methods Am Mittwoch, 9. Mai 2018, 11:19:54 CEST schrieb Albert Shih: I would like to know what's kind of backup method are recommended for cyrus-imapd. My cyrus-imapd host (only one currently) are running under FreeBSD jail (something like systemd-nspawn, lxc) & ZFS so I'm intend to use this method : stop the vm take a zfs snapshot start the vm send the zfs snapshot on a backup server. This is relatively inefficient, but a working option if anything from cyrus data is on that VM - i.e. the complete mail spool and the database files (possibly plus sieve files). We do similiar on relatively small systems or to get "intraday backups" only. On larger systems with VMs i take a ZFS or LVM snapshot and mount it externally to "fetch" a full (incremental) filesystem backup of the mail spool and imap spool and cyrus db on a daily base. After the backup run i destroy the snapshot. Beside this and depending from your needs you may take a look at cyrus replication features to build a "backup" or just use standard filesystem backup tools like tar, dumpfs etc. On a file base you have to backup the mail spool and the cyrus database files. If you use SIEVE, backup the SIEVE file pool too. You can restore by just replacing the files and start cyrus. To get the common database files "interoperable" it may makes sense to dump then into a machine independent format for backup if they are in a machine dependent format. If your restore such a filesystem based backup to a new system which has other hardware / arch specs or newer / incompatible DB subsystem (instead of skiplist) you may have to "recreate" indizes and database data. reconstruct - f may be your friend to "clean" up the transfer / restore. There are several strategies for backup cyrus - this are just a few. hth a bit. good luck, Niels. |
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