Low HDD perfomance/ Long wait io on jbd2

Nextcloud version (eg, 20.0.5):
Operating system and version (eg, Ubuntu 20.04): Ubuntu 20.04
Apache or nginx version (eg, Apache 2.4.25): nginx 1.18.0
PHP version (eg, 7.4): 7.4.3

The issue you are facing: High IO usage by jbd2 service

Is this the first time you’ve seen this error? (Y/N):y

Steps to replicate it:

  1. Install nexcloud
  2. update to
  3. get problem with HDD perfomance

The output of your Nextcloud log in Admin > Logging:


The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):

it works

The output of your Apache/nginx/system log in /var/log/____:

nothing intresting

Output errors in nextcloud.log in /var/www/ or as admin user in top right menu, filtering for errors. Use a pastebin service if necessary.


iotop screenshot


I have no idea why you post this issue in Nextcloud forum as the issue is completely unrelated to this application.

You screenshot show process jdb2 eating lot of CPU and mysql is the next one (but 8% sounds reasonable when the system is in use which seems to be the case according to php-fpm is active as well).

quick internet search show jdb2 is the driver for ext4 journaling and other hit the issue as well. please continue the troubleshooting at this point.

maybe this one is the most specific as it relates to both jdb2 and mysql…

|Thank you for fast reply. After analyze of cloud clients I have got that the files synchronization getting this result. After full files synchronisation jbd2 has been returned to normal IO activity.