Lockups with USB disks on FreeBSD

David Jackson djackson452 at gmail.com
Mon Mar 1 23:48:56 UTC 2010

David Jackson wrote:
> David Jackson wrote:
>> I am currently using FreeBSD 8.0. I have been, for a long time, been 
>> having problems with lockups of FreeBSD 8.0 when using USB hard 
>> disks. Sometimes certain applications lock up for several minutes, 
>> when they use the disk, file operations are very slow, and sometimes 
>> the entire operating system can lock up for several minutes. This can 
>> be a pretty painful thing and makes the system seem very unstable. I 
>> am using UFS filesystems on the disks. It seems to happen on multiple 
>> disks that i use.
>> I was hopeful changes to the FreeBSD USB drivers might have improved 
>> things but they are as bad as ever.
>> Help is appreciated.
> Are there perhaps diagnostic tools or an error log that can be enabled 
> so I can see if maybe there is some sort of error occuring with the 
> USB transmissions that might be causing this problem, or perhaps what 
> part of the driver code it is getting locked up on?.
> Has anyone else experienced problems such as this with USB disks? If 
> more information on my hardware is needed i will post dmesg output.
> Any help is appreciated.
I have done some more thinking about this issue. Just an app freeze on 
USB access is one thing, however, the fact that the entire OS freezes up 
on access to the USB disk shows there are much more serious design 
problems in the FreeBSD kernel. A USB access should not cause the kernel 
to lock up for minutes. these are very serious flaws in the FreeBSD 
kernel and lead to an instable and unuseable system. With these 
problems, and the fact no one really seems to care that the FreeBSD 
kernel is unstable, freezes up, etc , really is shocking considering 
FreeBSD bills itself as a server OS. Freezes and lockups are not a sign 
of stability or good design, they are evidence of severe design flaws, 
especailly that the entire kernel would freeze. I would be glad to use 
diagnostic tools to help find the problem. Much of the FreeBSD kernel 
however seems to be a black box, I have tried to study it but it seems 
to be badly documented. I have not been able to penetrate it and i do 
not know enough, despite my efforts, about it to understand what is 
causing these problems.

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