https://bugs.kde.org/show_bug.cgi?id=294772
Summary: Akonadi IMAP/maildir resource agent writes extensively
for long period after deleting a several thousand
e-mails
Product: kmail2
Version: 4.7
Platform: Gentoo Packages
OS/Version: Linux
Status: UNCONFIRMED
Severity: normal
Priority: NOR
Component: general
AssignedTo: kdepim-bugs@kde.org
ReportedBy: christian.bur...@gmail.com
Created an attachment (id=69073)
--> (http://bugs.kde.org/attachment.cgi?id=69073)
decompressed about 2 megabytes of strace log
Version: 4.7 (using KDE 4.7.4)
OS: Linux
I am using Akonadi 1.6.2 and KMail 4.7.4 on a Gentoo platform. I deleted
several thousand files in an IMAP folder (with activated disconnected feature)
and another thousand files in my local trash folder. This resulted in heavy
disk I/O about 15-20 MBytes/sec for at least 15 minutes, probably longer.
$ dstat
----total-cpu-usage---- -dsk/total- -net/total- ---paging-- ---system--
usr sys idl wai hiq siq| read writ| recv send| in out | int csw
22 10 41 26 0 0| 443k 6371k| 0 0 | 0 0 | 598 704
38 46 0 16 0 1| 0 37M| 0 0 | 0 0 |1718 731
18 17 0 64 0 1| 0 14M| 0 0 | 0 0 | 739 659
28 30 0 41 0 1| 0 26M| 0 0 | 0 0 |1319 545
19 22 0 58 0 0| 0 18M| 0 0 | 0 0 | 919 407
23 24 0 52 0 1| 0 17M| 0 0 | 0 0 | 889 614
23 23 0 53 0 1| 0 19M| 0 0 | 0 0 | 868 604
29 23 0 48 0 0| 0 19M| 0 0 | 0 0 | 980 501
9 7 0 83 0 1| 0 4880k| 0 0 | 0 0 | 259 171
11 8 0 81 0 0| 0 5140k| 0 0 | 0 0 | 313 587
17 12 0 71 0 0| 0 10M| 0 0 | 0 0 | 521 337
6 5 0 89 0 0| 0 2262k| 0 0 | 0 0 | 222 270
12 8 0 80 0 0| 0 5392k| 0 0 | 0 0 | 374 598
I traced the culprits to the Akonadi processes associated with the mail folders
from where I deleted the mails:
Both processes were truncating (down to zero) and writing one file each over
and over again:
1.
process as shown in ps: "/usr/bin/akonadi_agent_launcher
akonadi_maildir_resource akonadi_maildir_resource_2"
path to heavy i/o file:
~/.config/akonadi/agent_config_akonadi_maildir_resource_2_changes.dat
2.
ps: "/usr/bin/akonadi_imap_resource --identifier akonadi_imap_resource_12"
path: ~/.config/akonadi/agent_config_akonadi_imap_resource_12_changes.dat
At the beginning (at least the moment when I realized something was wrong) the
latter file was about 200 KBytes and the former about 2 MBytes. The file size
was shrinking each truncate/write cycle by a small amount (around 1
kilobytes/sec). I see no need for I/O of that magnitude, just because I deleted
a huge bunch of obsolete e-mails.
Just tried to reproduce the problem and it seems that pretty much any huge
change to a mail folder will have this effect. I copied an IMAP folder of a
thousand e-mails to my local mail folder and the fun begun.
Using a SSD I am pretty sure that this behaviour will shorten the lifespan of
my disk unneccessarily. By now I have migrated the problematic files
temporarily to a classic hard disk and will stay away from huge changes in my
mail folders without a hard disk at hand.
PS: I thought Linux's disk cache would take care of situations like that, but
my HDD LED is flickering like crazy.
Reproducible: Always
Steps to Reproduce:
either
delete a huge number (more than 1000) of e-mails from one folder
or
copy a huge number of e-mails from a IMAP folder to a local mail folder
Actual Results:
seemingly unnecessary I/O
Expected Results:
much less I/O
I have attached an unfiltered strace from one of the processes going wild.
Maybe bug #293175 is related to mine, but the information given there is too
little to be sure.
--
Configure bugmail: https://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
_______________________________________________
Kdepim-bugs mailing list
Kdepim-bugs@kde.org
https://mail.kde.org/mailman/listinfo/kdepim-bugs
