Exclude dovecot-uidlist files from a Maildir backup ?

David Pottage david at electric-spoon.com
Tue Jun 25 17:26:48 EEST 2019


Hi,

I am using restic to backup my email (stored in dovecot Maildir format) 
to Amazon S3

As each message is a separate file on disk, and those files don't change 
after the email has been delivered and read by the user, the incremental 
backup each day is fairly efficient as it only stored new mails.

However, the dovecot-uidlist files change frequently, and are often 
quite large. The restic backup program detects the file has changed and 
uploads a new version, but is not smart enough to detect that only a few 
lines have changed, so it uploads a fresh copy of the entire file to 
remote storage.

I have done some test backups and have noticed, that if I exclude those 
files from the backup, it completes much faster and uploads far less. 
Would this be a reasonable policy?

My backup is mainly there against unlikely but severe events such as 
complete hard drive failure, so if I ever had to use it, I would not 
mind wating for my email client to re-download all my emails.

-- 
David Pottage


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