Extreme console latency during disk IO (8.0-RC1, previous releases also affected according to others)

Greg Miller gmiller at classic-games.com
Fri Dec 11 18:44:09 UTC 2009

Ivan Voras wrote:

> Ivan Voras wrote:
>> Another data point - the OS in the VM in question hanged today 
>> sometime after 5 AM in the following way:
>>     * console nonresponsive (also to ctrl-alt-del)
>>     * ssh login nonresponsive (timeout)
>>     * ping works (!)
>> Judging by the last seen timestamp, the machine should have been in 
>> the process of receiving rsync backups - so IO-bound.
> It looks like something really could be fishy in this area, at least 
> with VMWare. The same thing happened again, and I have an additional 
> data point: I left 'top' running on the console and when I attached the 
> VMWare console to the VM, the top was still running ok, but as soon as I 
> hit a key on the keyboard, the OS console locked up. All other symptoms 
> were as I enumerated above.

A buildworld is enough to kill the console for me under QEMU on a slow 
Windows host. Never seen problems with a native install of FreeBSD, though.
http://www.velocityvector.com/ | http://www.classic-games.com/
      Any government that can give you everything you want
                  can take everything you have.

More information about the freebsd-stable mailing list