[OpenAFS-devel] strange problems with qemu and 1.4.0-rc3?

[Derek Atkins]

Quoting Troy Benjegerdes <hozer@hozed.org>:

> On Wed, Sep 14, 2005 at 09:49:14PM -0400, Derek Atkins wrote:
>> Sounds like qemu either doesn't like blocking, or is putting itself into
>> non-blocking mode but not dealing when the filesystem can't provide data as
>> fast as it wants.   So... sounds like a qemu problem to be.
>
> Is there any good way to track down what's misbehaving? I'm sure the
> qemu people will blame the filesystem..

Well, it all depends on your definition of "track down".  It takes a non-zero
amount of time to download an ISO image.  If the data isn't in the cache yet,
the filesystem will block waiting for the response.  The filesystem is 
behaving
just fine -- it's a question of how qemu deals with this situation.  As 
a test,
try running NFS over, say, a serial line with PPP and see if qemu fails in the
same way.

I know nothing about qemu, but I can assure you that VMware works just fine
booting from an ISO out of AFS, so I'm absolutely confident the problem 
lies in
qemu's dealing with the filesystem delays.   Indeed, I read ISOs out of AFS
with VMware all the time to install OSes.

-derek

-- 
       Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
       Member, MIT Student Information Processing Board  (SIPB)
       URL: http://web.mit.edu/warlord/    PP-ASEL-IA     N1NWH
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