Nextcloud gallery REALLY slow, mysql high cpu, high disk io for writes [FIXED!]

lara · February 18, 2018, 8:00pm

Here’s how I fixed it:

Pre-generated previews
php /var/www/nextcloud/occ preview:pre-generate
Installed Redis for the locks (really! the gallery went from FAST-slow-slow-slow-slow to FAST-fast-fast-fast)
https://docs.nextcloud.com/server/13/admin_manual/configuration_server/caching_configuration.html

(memcached was already installed)

lara · February 19, 2018, 6:22pm

Oh no! It got slow again!

Schmu · February 19, 2018, 6:36pm

Can you monitor with system tool top where the performance gets lost (CPU, RAM, HDD (io-wait)) and maybe which process is consuming the resources?
Furthermore, please provide information about your system and also provide system logs and nextcloud log.

Best would be to use the issue template which is available via app:
https://apps.nextcloud.com/apps/issuetemplate

It helps to not miss out important information so we can help best and much faster.

lara · February 19, 2018, 8:10pm

I changed the caching mode on the hypervisor to writeback AND removed the previews. Now I am regenerating the previews.

Maybe the large number of previews is the bottleneck or maybe the caching method (no ssd). I will come back and tell you.

lara · February 20, 2018, 7:25pm

@schmu the problem comes with lots of files. 10000 files in a directory and nextcloud gets slow