Hello, everybody,

I am a administrator of a medium large mail system. And now the mail
spool are larger than 10G. I feel very headache about the messages
backup.

When it not so big as now, i use tar to backup the mail spool. Now it's
too big to use the original method to backup it.

Is there any good method to do so?

Maybe be some sync tools could me, such as rsysc or anything else?

My email system is built up with cyrus-imapd and postfix on a gentoo
box.

Thanks very much.

Every reply is appreciated.

Wang Penghui

HI.

I do the following to backup about 14gb data of Cyrus-imap server:

1. I backup the whole server using "tar" (or "star") to tape, every day.
I do keep at least one week history of these tapes.

2. I have an additional local hard disk on the server,
and I use "rsync" to store a copy of the whole server on the second hard disk every day.

I'm not sure if these are the best methods, but they are fine for me.

Yizhar Hurwitz
http://yizhar.mvps.org

Thanks very much for your advice. But i think my problem is a little
different from yours. The email server is remote server and this is the
only server. And there is no extra harddisk in the server. And the
network between my backup server and the email server is not so good.

And large data is not suitable to transfer between the backup server
and the email server. No extra harddisk, so i could not rsync the mail
spool from the working harddisk to the extra harddisk.

Is there any incremental backup method suitable for my situation?

Best regards

Wang Penghui

"Wang Penghui" <wangpenghui@gmail.com> writes:

> Is there any incremental backup method suitable for my situation?

With rsync (over SSH for security), only the blocks of data that are
changed are copied over. Of course the first you run rsync the entire
contents will have to be copied over.

What OS are you running? It may be possible to do incremental backups
with other programs ((ufs)dump, star (Schilly tar), cpio combined with
find).

--
David Magda <dmagda at ee.ryerson.ca>
Because the innovator has for enemies all those who have done well under
the old conditions, and lukewarm defenders in those who may do well
under the new. -- Niccolo Machiavelli, _The Prince_, Chapter VI

> What OS are you running? It may be possible to do incremental backups
> with other programs ((ufs)dump, star (Schilly tar), cpio combined with
> find).

For what it is worth, I have been using (GNU) Tar to do incremental and differential backups for a number of years. I do so by using the "--newer" option. After every backup I echo the date in to a file that I then read said date out of during my next backup cycle. This way I can find all files that are ""newer than the last backup cycle. I have written a backup script for my web sites (that should work for your mails spool too) that creates a monthly full backup and then every week it creates a differential backup from the monthly backup. The script also creates daily incrementals of changes from the previous day.

If you would like email me off news and I'll email you a copy of the script. It's not the cleanest thing, but it does get the job done. Also most importantly I have successfully restored from the backups (users messing up their own web pages...) so the most important part of the backup, restoration, has been tested.



Grant. . . .

Wang Penghui wrote:
> Thanks very much for your advice. But i think my problem is a little
> different from yours. The email server is remote server and this is the
> only server. And there is no extra harddisk in the server. And the
> network between my backup server and the email server is not so good.
>

HI.

In that case, you can try utilities that work using IMAP protocol,
such as imapsync

How many mailboxes do you have on the imap server?

Do you really need to store *all* the 10gb there?
Maybe some manual cleaning and archiving of old and large messages will ?

And/or you can consider implementing your own imap server.

Yizhar

There about 20 virtual domains with more than 1000 mailboxes. I am not
sure the imapsync workable for me or not, But i will do some test with
it.

And all the data should be backuped. Because of all of them are in a
production server. I could not let any letter missed,

I think a incremental backup is the best solution.

Thank very much

Wang

> There about 20 virtual domains with more than 1000 mailboxes. I am not
> sure the imapsync workable for me or not, But i will do some test with
> it.

*cough* That would be less than fun to back up on a per account basis.

> And all the data should be backuped. Because of all of them are in a
> production server. I could not let any letter missed,

I pose a question to you. What do you want the backup to protect against / provide? Are you wanting to protect against hardware failure? Or are you trying to protect against some sort of data corruption (presuming good hardware) such as someone editing a file (not so pertinent for email as word documents) with multiple versions? How important is it to be able to restore a message after a user deletes it?

> I think a incremental backup is the best solution.

Possibly. I think knowing what you are wanting the backup to protect against will better answer this question.



Grant. . . .

> Maybe be some sync tools could me, such as rsysc or anything else?

Hmm, Maildir is nice. I'm not sure what options are open to you with Cyrus. Thankfully it looks like individual messages are stored as individual files with in the ""data base. However it looks like there are a few key files with in mailbox directories which may pose a bit of a problem.

> My email system is built up with cyrus-imapd and postfix on a gentoo
> box.

Am I correct in presuming that you have control of the mail server and thus could make kernel level changes?

What I would be tempted to do would be to try setting up a similar system as an additional (read backup) mail server. I would then try to utilize a replicating network based file system that could (close to real time) transfer data from one server to another. This will allow you to have your backup at the end of the day. However this will not protect against someone deleting / altering / corrupting files (hens why I asked what you wanted your ""backup to provide in a different post).



Grant. . . .