Very high iowait on VDS, storage optimization stuck

I had terrible iowait on my RS8000 G11, processor almost idle, about 3-4 Mbps of reads/writes on disk but iowait reached 30-50% sometimes even 80%.

top - 15:02:19 up 40 days, 22:59,  2 users,  load average: 8.13, 13.54, 12.58
%Cpu(s):  6.2 us,  1.5 sy,  0.0 ni, 64.9 id, 27.1 wa,  0.0 hi,  0.4 si, 
0.0 st
MiB Mem :  64298.0 total,   2357.5 free,  15335.8 used,  46604.7 buff/cache

The server was unusable. Support isn't responding. I decided to run a disk optimization via the panel, but it’s stalled for more than an hour so I’m almost sure that there’s some problem with storage on netcup side. Maybe someone here can help me with this?

Server came back to live but iowait problem still persists.

Screenshot_20261002-120945_Termux~2.jpg

Server is showing 20% iowait even with no services running. There is clearly an issue with the disk array, and I find it hard to believe that no one at Netcup is monitoring this, not to mention complete lack of support. I have €2 LXC VPSs that currently have faster disks than this RS8000.

Server has been moved to another node and works fine now.