On 2019-02-03 21:12, Philon wrote:
On 03 Feb 2019, at 22:07, MRob mrobti@insiberia.net wrote:
Hi, I originally picked mdbox because I had the impression from reading about it on the mailing list that it was more performant and that it would conserve disc space.
But lately i found mailboxes have nearly double the storage as reported. I mean, IMAP QUOTA reports around 900MB for one account that has over 2GB when I inspect the mail location of the user using the linux command
duAnother account has around 750MB according to IMAP but using du I find 1.5GB. This is for message files and index files combined.
Is this normal? I tried to read the MailboxFormat/dbox wiki page and it does not directly address this topic but it does reference "doveadm purge". Do I need to use "doveadm purge"?
From https://wiki2.dovecot.org/MailboxFormat/dbox:
Expunging a message only decreases the message's refcount. The space is later freed in "purge" step.
Thats what I read but I had a hard time to believe I could understand it was a critical maintenance because it was not highlighted in the docs.
I ran purge and find now "du" reporting about 60% the size of IMAP QUOTA so mdbox now is saving space and I'm very happy for Dovecot again is good software. But may I ask developers it is not common belief of administrators to know they must purge message storage - can you please make this a warning in highlight and big text on the mailformat documentation? I think this is a ciritcal oversight
PS for 10.000+ users how heavy is this process on performance? what if 100.000+ users?