Arch Linux

toorlv

Member

Registered: 2009-11-01

Posts: 65

kjournald2/pdflush writes to disk about every 3-4 seconds

Every few seconds the disk writes (or reads - i have no idea).
iotop shows it to be kjournald2. kjournald2 only shows up in system monitor if it is launched with sudo.
Arch i686, ext4, Pentium M 1.7 GHZ, Fujitsu-Siemens L1300.
(I also tried to disable/enable laptop-mode, played with noatime/nodiratime options, disabled/enabled hal/dbus, tried other distros with ext4 - same result.)

pdflush(15): dirtied inode 1089 (iotop) on sda7
pdflush(15): WRITE block 1297744 on sda7
pdflush(15): dirtied inode 363 (?) on sda7
pdflush(15): WRITE block 1297752 on sda7
pdflush(15): WRITE block 1297760 on sda7
pdflush(15): WRITE block 1297768 on sda7
pdflush(15): WRITE block 1297776 on sda7
pdflush(15): WRITE block 1297784 on sda7
kjournald2(484): WRITE block 1295248 on sda7
kjournald2(484): WRITE block 1297640 on sda7
kjournald2(484): WRITE block 4468584 on sda7
kjournald2(484): WRITE block 4468592 on sda7
kjournald2(484): WRITE block 4468600 on sda7
kjournald2(484): WRITE block 4468608 on sda7
kjournald2(484): WRITE block 4468616 on sda7
kjournald2(484): WRITE block 4468624 on sda7
kjournald2(484): WRITE block 4468632 on sda7
kjournald2(484): WRITE block 4468640 on sda7
kjournald2(484): WRITE block 4468648 on sda7
kjournald2(484): WRITE block 4468656 on sda7
kjournald2(484): WRITE block 4468664 on sda7
kjournald2(484): WRITE block 4468672 on sda7

~/  iotop -o -d 3 -b
Total DISK READ: 0.00 B/s | Total DISK WRITE: 0.00 B/s
  TID  PRIO  USER     DISK READ  DISK WRITE  SWAPIN      IO    COMMAND
Total DISK READ: 0.00 B/s | Total DISK WRITE: 0.00 B/s
  TID  PRIO  USER     DISK READ  DISK WRITE  SWAPIN      IO    COMMAND
Total DISK READ: 0.00 B/s | Total DISK WRITE: 15.80 K/s
  TID  PRIO  USER     DISK READ  DISK WRITE  SWAPIN      IO    COMMAND
  484 be/3 root        0.00 B/s    0.00 B/s  0.00 %  2.98 % [kjournald2]
  TID  PRIO  USER     DISK READ  DISK WRITE  SWAPIN      IO    COMMAND
 4104 be/4 root    0.00 B/s    2.63 K/s  0.00 %  0.00 % [kjournald2]
Total DISK READ: 0.00 B/s | Total DISK WRITE: 24.99 K/s
  TID  PRIO  USER     DISK READ  DISK WRITE  SWAPIN      IO    COMMAND
  484 be/3 root        0.00 B/s   13.15 K/s  0.00 %  2.05 % [kjournald2]
Total DISK READ: 0.00 B/s | Total DISK WRITE: 0.00 B/s

Last edited by toorlv (2009-11-17 11:02:23)

rwd

Member

Registered: 2009-02-08

Posts: 664

Re: kjournald2/pdflush writes to disk about every 3-4 seconds

I experienced the same thing on my Intel Atom 270 (32bit) system, preventing my disks from spinning down. After upgrading the kernel from 2.6.31.6-1 to 2.6.32.2-2  kernel.log gets filled with this:

Jan  2 19:29:37 arch-server kernel: mv(16920): WRITE block 280400 on dm-1
Jan  2 19:29:37 arch-server kernel: mv(16920): WRITE block 280408 on dm-1
Jan  2 19:29:37 arch-server kernel: mv(16920): WRITE block 280416 on dm-1
Jan  2 19:29:37 arch-server kernel: mv(16920): WRITE block 280424 on dm-1
Jan  2 19:29:37 arch-server kernel: mv(16920): WRITE block 280432 on dm-1
Jan  2 19:29:37 arch-server kernel: mv(16920): WRITE block 280440 on dm-1
Jan  2 19:29:37 arch-server kernel: mv(16920): WRITE block 280448 on dm-1
Jan  2 19:29:37 arch-server kernel: mv(16920): WRITE block 280456 on dm-1
Jan  2 19:29:37 arch-server kernel: mv(16920): WRITE block 280464 on dm-1
Jan  2 19:29:37 arch-server kernel: mv(16920): WRITE block 280472 on dm-1
Jan  2 19:29:37 arch-server kernel: mv(16920): WRITE block 280480 on dm-1
Jan  2 19:29:37 arch-server kernel: mv(16920): WRITE block 280488 on dm-1
Jan  2 19:29:37 arch-server kernel: mv(16920): WRITE block 280496 on dm-1
Jan  2 19:29:38 arch-server kernel: dmesg(16924): dirtied inode 11 (dmesg_next) on dm-1
Jan  2 19:29:38 arch-server kernel: dmesg(16924): dirtied inode 11 (dmesg_next) on dm-1
Jan  2 19:29:38 arch-server kernel: dmesg(16924): dirtied inode 11 (dmesg_next) on dm-1
Jan  2 19:29:38 arch-server kernel: kjournald2(2918): WRITE block 1062024 on dm-0
Jan  2 19:29:38 arch-server kernel: kjournald2(2918): WRITE block 285481888 on dm-0
Jan  2 19:29:38 arch-server kernel: kjournald2(2918): WRITE block 285481896 on dm-0
Jan  2 19:29:38 arch-server kernel: kjournald2(2918): WRITE block 285481904 on dm-0
Jan  2 19:29:38 arch-server kernel: kjournald2(2918): WRITE block 285481912 on dm-0
Jan  2 19:29:38 arch-server kernel: kjournald2(2918): WRITE block 285481920 on dm-0
Jan  2 19:29:39 arch-server kernel: kjournald2(2918): WRITE block 285481928 on dm-0
Jan  2 19:29:39 arch-server kernel: mv(16943): WRITE block 268288 on dm-1
Jan  2 19:29:39 arch-server kernel: mv(16943): WRITE block 268296 on dm-1
Jan  2 19:29:39 arch-server kernel: mv(16943): WRITE block 268304 on dm-1

After downgrading the kernel it went away. I wonder which package I should file a bug for, simply the kernel?.

Ubuntu and Mandriva are affected as well. It seems specific for ext4 filesystems.

https://bugs.launchpad.net/ubuntu/+bug/442443
https://bugs.launchpad.net/ubuntu/+sour … bug/483569
https://qa.mandriva.com/show_bug.cgi?id=56245

Last edited by rwd (2010-01-03 11:51:57)