doveadm backup mdbox - initial copy slow
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 "statusmails@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
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 "statusmails@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
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 "statusmails@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
Thanks Aki, that did the trick!
Calling /usr/bin/doveadm -o plugin/quota= -o mail_fsync=never backup -u "statusmails@domain.com" "mdbox:/backup/vmail/domain.com/statusmails" finished in 2 secs [changes:1925 copy:1925 delete:0 expunge:0]
Best regards Gerald
participants (2)
-
Aki Tuomi
-
Gerald Galster