Many processes stuck in zfs

[Alexander Leidinger]

Quoting Borja Marcos <borjam at sarenet.es> (from Thu, 11 Mar 2010  
09:54:47 +0100):

>
> On Mar 11, 2010, at 8:45 AM, Alexander Leidinger wrote:
>
>> Quoting Pawel Jakub Dawidek <pjd at FreeBSD.org> (from Wed, 10 Mar  
>> 2010 18:31:43 +0100):
>>
>> There is a 4th possibility, if you can rule out everything else:  
>> bugs in the CPU. I stumbled upon this with ZFS (but UFS was  
>> exposing the problem much faster). The problem in my case was that  
>> the BIOS was not recognizing the CPU and as such was not uploading  
>> microcode updates.
>>
>> Borja, can you confirm that the CPU is correctly announced in  
>> FreeBSD (just look at "dmesg | grep CPU:" output, if it tells you  
>> it is a AMD or Intel XXX CPU it is correctly detected by the BIOS)?
>
> A CPU bug? Weird. Very.

It depends. CPUs have bugs. You do not want to run any modern CPU  
without an microcode update. The BIOS is doing it for you at system  
start.

I do not want to say that this is the problem you have, I just want to  
point out that it may be possible (but see below). I got hit by this  
last december and I was finding the solution (replacing the complete  
system, as only replacing the CPU was not an option) in January.

> As the servers had to be rolled into production, and such tests with  
> real servers can be quite time consuming, I set up a couple of  
> FreeBSD virtual machines, using VMWare Fusion (version 2 then, now  
> version 3) on a Macbook (Macbook 4,1 Intel Core2Duo, 2.1 GHz) and  
> tried to reproduce it.

> Timecounter "i8254" frequency 1193182 Hz quality 0
> CPU: Intel(R) Xeon(R) CPU           L5420  @ 2.50GHz (2496.25-MHz  
> K8-class CPU)
>   Origin = "GenuineIntel"  Id = 0x1067a  Stepping = 10

> The virtual machine (VMWare Fusion 3.0.0, Macbook, Mac OS X 10.6.2)  
> reports this:
> Timecounter "i8254" frequency 1193182 Hz quality 0
> CPU: Intel(R) Core(TM)2 Duo CPU     T8100  @ 2.10GHz (2116.62-MHz  
> K8-class CPU)
>   Origin = "GenuineIntel"  Id = 0x10676  Stepping = 6

Summary: you confirmed the problem on a different kind of CPU.

Because of this it makes it even more unlikely that it is a CPU problem.

Bye,
Alexander.

-- 
A good plan today is better than a perfect plan tomorrow.
		-- Patton

http://www.Leidinger.net    Alexander @ Leidinger.net: PGP ID = B0063FE7
http://www.FreeBSD.org       netchild @ FreeBSD.org  : PGP ID = 72077137