Sites began to slow down after switching to VPS. What to do with large disk write from mysqld?

Question

MySQL

Sites began to slow down after switching to VPS. Technical support answered the following:
Various factors can affect the speed of loading sites. Most often, slow loading is associated with high traffic, slow site scripts and database queries.
Due to the large number of sites on your server, we cannot say exactly which site has the highest load.
According to the output of the top command, we see that the following processes have the greatest load on the CPU and memory:
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
705 MySQL 20 0 1572444 421076 8548 S 60.2 20.6 43: 24.88 MySQLD
10036 ROOT 20 0 4632 1432 1148 R 56.0 0.1 0: 02.29 GZIP 3305 Admin
20 0 575520 130052 76632 S 33.0 6.4 1: 55.46 APACHE2 APACHE2
6016 admin 20 0 556084 111184 76772 R 17.2 5.4 0: 52.37 apache2
10035 root 20 0 29660 3200 2788 R 14.6 0.2 0: 00.75 tar
5989 admin 20 0 493592 98636 50920 S 8.1 4.8 1: 03.79 apache2
4648 admin 20 0 562664 117080 76044 R 2.6 5.7 0:53.56 apache2

I myself read and stumbled upon the iotop -oka utility, after launching which I saw that one process was eating disk write.

How to proceed here and track which site this load is from? I myself am a layman in this matter, on hosting they were actually forced to switch to VPS, as there was a high load and excess of SR

Answer 1

Hire an admin
See the halls through the show process sheet in muscle

Answer 2

VPS is almost always weaker than regular hosting, at the time of the request, all hardware resources are available on the hosting, and on VPS everything is truncated. Now I definitely don’t see nginx, if I try to put nginx for statics in front? Or do you also sell hosting?

Answer 3

If the load is constant, then by elimination. And see the output of mytop

Answer 4

Monitor slow queries to mysql. Explicitly check which indexes are used exactly on the combat mysql, since even on the dump other indexes can be used.
If you have a very active record, look towards batch insertion and partitioning. The second is worth touching if you have at least 1kkk records in one table.

Answer 5

Hire an admin, set up mysql
The problem is that hosting has already optimized service settings. On a VPS, you have to do everything yourself.
In principle, if you find me in PM tonight, I'll look at your server)

Answer 6

someone writes to the database for a long time,
look who has a suspiciously large database
, as well as joomla and so on like engines.
They are often attacked, for example, they can write a bunch of posts in the forum