(Renamed subject from [PATCH] Support transient attribute on vmware disks) On Dec 27, 2013, at 22:59 , Eric Blake <eblake@redhat.com> wrote:
On 12/27/2013 02:40 PM, Wout Mertens wrote:
Otherwise it seems to me that this would be part of the general section, perhaps simply a “path” node?
Not quite a path node. I was thinking more like:
<domain type='kvm'> <name>foo</name> <pool name='mypool'/> ...
where the new <pool> element says that anything that the 'foo' domain does that requires creation of new files will do so within the already existing <pool> object with the name 'mypool'. We can also support <pool uuid='...'> (or both name and uuid at once). If the <pool> element is missing, that's when the domain uses defaults and/or refuses to do tasks where we don’t know where to stick the files.
Yes, that seems like a nice interface. It does throw away some info (the full path to the .vmx file in the case of VMWare) but that doesn’t really matter very much. I had a look at implementing this but I’m stuck. I don’t know the code very well, I figure there are at least three places this impacts (for vmware): - (1) the virDomainDef definition - (2) the translation from virDomainDef to .vmx file path - (3) (optionally I suppose) the translation from .vmx file to virDomainDef For (1), I added a sub-struct to _virDomainDef in domain_conf.h: struct { char *name; char *uuid; } pool; …thinking this would be easier than managing a pool object pointer and a more direct representation of the domain xml. Is there any change to definition or initialization code etc needed elsewhere? Testing code? For (2): The translation from virDomainDef to path happens in vmware_conf.c:vmwareVmxPath() and there the problem is that regular VMWare uses a full path but ESX uses the ‘[storage] ‘ prefix instead. - I presume there’s somewhere in the pool management code that translates this, any pointers? - vmware_conf.c then needs to pull in the storage_conf.h file, is that a problem? - I propose that if both UUID and name are present, UUID takes precedence over name, but if no device is found then name is tried. I haven’t tackled (3) yet and I suppose it doesn’t really add much, certainly not for my use case. Happy 2014! :) Wout.