On 30.8.2019 12.33, Gerald Galster via dovecot wrote: > Hello, > > when calling doveadm backup like in the following example, it seems to flush > every email to disk > maxing out harddrives (iops) and resulting in very poor performance: > > Calling doveadm -o plugin/quota= backup -u "statusma...@domain.com" > "mdbox:/backup/vmail/domain.com/statusmails" > finished in 212 secs [changes:1800 copy:1800 delete:0 expunge:0] > > The source mdbox holds 1800 small emails and uses about 20 MB disk space only. > > I've tried -f (full sync) and -l 30 (locking the mailbox) which did not get > faster, nor did doveadm sync -1. > > When using doveadm import all mails are copied in less than 3 seconds: > time doveadm -o mail=mdbox:/backup/vmail/domain.com/statusmails import > mdbox:/var/vmail/domain.com/statusmails "" all > real 0m2.605s > > Are there any other options I could try to speed up doveadm backup, avoiding > the flush after each email? > > This is doveadm from dovecot 2.2 (>= 2.2.33). Does anyone get better results > with 2.3 tree? > > Best regards > Gerald
Try setting mail_fsync=never Aki
