I recently performed the following test to see what happens I/O-wise when a message is deleted from a 'large' (~80k messages) mbx-format INBOX.
To my surprise, ~800MBs of write activity ensued. I was wondering if anyone could help me understand why. The filesystem in question is ext4. imap-2007e I can provide all of my data on request. 1. copy a 1GB mbx-format mailbox (mailutil check INBOX returns no errors) composed of 1KB to 256KB messages (random) to /home/mailtest/INBOX 2. start strace (strace -T -ttt -f -o strace.out -p 2138) - 2138 is xinetd's pid on my system - xinetd 'serves' only imapd 3. open Thunderbird - create an account for [email protected] - click on Server Settings - change "When I delete a message:" to "Remove it immediately" - check "Expunge Inbox on exit" - click on Synchronization & Storage - uncheck "Keep messages for this account on this computer" - under Edit -> Preferences -> Advanced -> General - uncheck "Enable Global Search and Indexer" 4. click on a message in the 'middle' of the INBOX 5. start a wireshark trace - LOGIN is allowed if SSL is not in use (for this test only) 6. delete the message selected in step 4 7. close Thunderbird 8. stop the wireshark trace 9. stop strace 10. Run 'strace analyzer' (http://clusterbuffer.wetpaint.com/ page/Strace+Analyzer+-+Next+Generation) on strace.out Thanks, Nathan Olson Systems Administrator North Dakota State University [email protected] 701-231-8579 _______________________________________________ Imap-uw mailing list [email protected] http://mailman2.u.washington.edu/mailman/listinfo/imap-uw
