2 bonnies can stop disk activity permanently

[R. B. Riddick]

Hi!

We (me and Veronica) mentioned, that starting 2 bonnie (ports/bench) processes on a UFS
1. on a geom_bsd, geom_disk (like ad4 or da0) and geom_stripe (using ad4a, ..., ad10a)
2. with different controllers areca and nVidia and different motherboards and
3. with up to 8 SATA disks
results in a permanently disk-dead system.


Veronica's box had more than 700MB of free memory (according to top), when it happened.

Heavy load (caused by blogbench, rawio, raidtest and dd) causes no problem, while bonnie gets stuck somewhere between putc phase and end of rewrite phase.

The bonnie processes were blocked due to "nbufkv" (some VFS reason).
Geom activity is impossible then (no file system activity happens).
No syslog message can be seen on the console.

Bye
-A&V