[CRIU] [RFC] Introduce v1.1 image format

[Pavel Emelyanov]

On 03/31/2015 04:07 PM, Ruslan Kuprieiev wrote:
> 
> On 03/31/2015 03:29 PM, Pavel Emelyanov wrote:
>> Hi,
>>
>> Right now we have too many criu-specific file types -- effectively
>> every new image file we add is a new "type", we invent a new magic
>> number for it and put only it into the header.
>>
>> One of the difficulty with this approach is that we can't nicely
>> teach the "file" utility to spot CRIU-specific files. Too many
>> magic should be added and we would have to add new magic numbers
>> for every new image type we introduce.
> 
> But this patch leaves inventory.img intact, so "file" utility might as 
> well just be taught to spot only inventory magic, because our images 
> are spread across directory anyway.

Yes, and asking "file" for what the rest is would result in an unhelpful
answer -- "data" :)

> Do we really need these changes?

With this we will only need to add 4 magic-s in the file database.

> This set also adds another level of confusing complexity to our images 
> structure.
> Maybe we should rather suggest focusing on V2 images, to make them 
> perfect and
> not create an intermediate version of non-backward compatible images?

V2 would be great, but they will be backward incompatible too :) So
from this perspective v1.1 is not worse.

-- Pavel