Re: xend deprecation

[Zhigang Wang <zhigang.x.wang@oracle.com>]

On 10/21/2013 10:09 AM, Wei Liu wrote:
> On Wed, Sep 04, 2013 at 10:04:14AM -0400, Konrad Rzeszutek Wilk wrote:
> [...]
>> There are issues that are stopping us from using it:
>>
> 
> I look at these xl items from time to time and see if I can fix them but
> they come out a little bit more complex than I expect.
> 
> Xl will store DomU configs in its private storage location and retrievs
> them as it see fit. This behavior is causing a series of issues.
> 
> For 'xl list -l', the detail info of a domain is retrieved from the
> stored config file.
> 
>>  - No status in xl list -l when only dom0 is present.
> 
> This would not work because there is no config file for Dom0.
> 
>>  - 'xl list -l' says 'Domain name must be specified' even though the '-l'
>>    is for 'Output all VM details'
> 
> Haven't traced this one down, but I presume this is caused by the same
> thing.
> 
>>  - No console in xl list -l, so can't get  tty console port.
> 
> This would not work because apparently you cannot specify a tty in
> DomU's config file -- that's allcoated by xenconsoled.
> 
> Along with the above issues, xl save/restored will only use the stored
> config file which makes it impossible to persist any runtime info across
> save/restore -- one significant defect is that VM's MAC address changes
> every time unless it is specified in the original config file.
> 
> These issues are all connected in a way -- runtime info is not retrieved
> / updated / preserved. What I have in mind is that we might need to
> introduce a mechanism to pull info from Xenstore, serialize /
> deserialize config info / update stored config file when necessary.
> 
> Comments?

Long time ago, when I work on it, I have the same feeling (I haven't
confirm the latest code yet).

xend is a daemon: it handles all VM state change. With xl, a private
storage location for each VM is the corresponding solution for now.

My suggestion with my limited knowledge is: remove this private storage
location and get all the info from xenstore/hypercall.

Thanks,

Zhigang