Re: [PATCH] Introduce dom0-min-space configuration option

[Michal Novotny <minovotn@redhat.com>]

On 07/21/2010 03:25 PM, Ian Jackson wrote:
> Michal Novotny writes ("Re: [Xen-devel] [PATCH] Introduce dom0-min-space configuration option"):
>    
>> Ian, the problem is when pygrub extracts the vmlinuz and initrd for PV
>> guests but there's insufficient space on the dom0, there's no error
>> message but the error is being raised from Xend itself, [...]
>>      
> So the correct fix is to make sure the error propagation works
> correctly.
>
>    

Well, the patching in the all the parts of the code may be better but 
there may be many issues caused there by dom0 being out of space and not 
all of them have to be xen related - nevertheless users can think 
they're xen related until they find out the dom0 is out of space and 
therefore although Xen may *not* be responsible they can blame Xen for that.

>>   libxc to be precise since there's the zStream inflation code but
>> since the input data are not valid (i.e. they're just partial,
>>      
> That suggests that not only is the error being bungled somewhere, it's
> being outright ignored and something tries to decompress the truncated
> file.
>    

Well, there's no other way to fix it than to implement a check for 
enough space on dom0 for extracting vmlinuz and initrd files from the 
image file. If it's partially extracted it's understandable that the 
data are not valid input for zStream processing and therefore it runs 
into Z_BUF_ERROR (-5) during the process.

> These bugs should be fixed.
>
> But I think your patch is entirely wrong, I'm afraid.
>
> Ian.
>    

Why do you think my patch is entirely wrong? If you're talking about 
functionality it's been tested on x86_64 RHEL-6 guest with upstream Xen 
installed.

Michal

-- 
Michal Novotny<minovotn@redhat.com>, RHCE
Virtualization Team (xen userspace), Red Hat