Zabbix Disabling Journaling on ext4

Zabbix server 2.2.3 (VM on VMWare 5.5) OS: CentOS release 6.5 (Final)

CPU utilization metrics: before cpu utilization

Task: Disable journaling on ext4.

HDD:

[root@v11 /]# df -T
Filesystem           Type  1K-blocks    Used Available Use% Mounted on
/dev/mapper/vg_zab-lv_root
                     ext4   14356848 6182300   7445256  46% /
tmpfs                tmpfs    961212       0    961212   0% /dev/shm
/dev/sda1            ext4     495844   54392    415852  12% /boot

Check filesystem characteristics:

[root@v11 /]# dumpe2fs /dev/mapper/vg_zab-lv_root |grep journal
dumpe2fs 1.41.12 (17-May-2010)
Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize
Journal features:         journal_incompat_revoke

Executed on a live system:

[root@v11 /]# tune2fs -o journal_data_writeback  /dev/mapper/vg_zab-lv_root
tune2fs 1.41.12 (17-May-2010)

Verifying:

[root@v11 /]# tune2fs -l /dev/mapper/vg_zab-lv_root | grep writeback
Default mount options:    journal_data_writeback user_xattr acl

Rebooted the server. Checked. No expected effect.

Shut down the server. Booted from a LiveCD that has LVM support (GParted LiveCD 0.19.1-1). Activated LVM:

user@debian:~$ sudo lvm vgchange -ay
 2 logical volume(s) in volume groue "vg_zab" now active

Completely disabled journaling on the partition:

user@debian:~$ sudo tune2fs -O ^has_journal /dev/mapper/vg_zab-lv_root
tune2fs 1.42.11 (09-Jul-2014)

Rebooted the server. Checked iotop — the system journaling process is no longer in the top lines. After a brief analysis, I concluded that the regular messages correspond to the hourly Housekeeper process, which heavily loads the database.

Conclusions: 1. No effect from disabling journaling on this configuration. 2. With this number of hosts, I don't see this event as critical.