I have strange issue with Wordpress on my server. After installing WP, some sites of admin panel require over 3-4 minutes to load. There are these "some" :
PluginsThemesDashoboard main siteImport
Posts are also loaded inpropertly. It's very confusing because ONLY for these sites errors occur. It doesn't seem to be a server configuration problem because the same server manage with other websites (Joomla etc.) . It's really fast as well as conncetion from ISP.
The question is: Is there something (missing) in wp-config.php , wp-setting.php or other files that might caused such a bizzare slow of loaded pages? What about server configuration?
I set up a new WP so there is no plugins or other stuff installed. Memory limit is set to 128MB. Page analyzers show long time for redirect from /wp-admin to /wp-admin/ and connection errors to mysite.com/wp-admin. (without details). Google PageSpeed Insights show me timeout so I suppose that others analyzers mean the same.
Any help would be appreciate. Thank you in advance! :)
UPDATE
I looked at database and some variables at summaration and there are lots of records that I am worry about. I am not sure is this caused by Wordpress or server configuration is guilty but that is what i have spotted:
Handler_read_rnd 29 M
Handler_read_rnd_next 172 M
Qcache_lowmem_prunes 103 k
Created_tmp_disk_tables 147 k
Select_range_check 19 k
Opened_tables 12 k
Select_full_join 2 296
Table_locks_waited 930
There is nothing beside Wordpress on server. So in database
