Re: [TESTDAY] xl restore gives an error too soon after xl save

[George Dunlap <George.Dunlap@xxxxxxxxxx>]

> On Jun 9, 2020, at 5:56 PM, Paul Durrant <xadimgnik@xxxxxxxxx> wrote:
> 
>> -----Original Message-----
>> From: George Dunlap <George.Dunlap@xxxxxxxxxx>
>> Sent: 09 June 2020 17:45
>> To: Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxxx>
>> Cc: Paul Durrant <paul@xxxxxxx>; Ian Jackson <Ian.Jackson@xxxxxxxxxx>; Wei 
>> Liu <wl@xxxxxxx>; Anthony
>> Perard <anthony.perard@xxxxxxxxxx>
>> Subject: [TESTDAY] xl restore gives an error too soon after xl save
>> 
>> Somewhat surprising that if you save with -D, you get mysterious error 
>> messages for the next so-many
>> seconds:
>> 
>> root@immortal:/images# xl save -D c6-01 /images/tmp/c6-01.save
>> Saving to /images/tmp/c6-01.save new xl format (info 0x3/0x0/950)
>> xc: info: Saving domain 19505, type x86 PV
>> xc: Frames: 524288/524288  100%
>> xc: End of stream: 0/0    0%
>> root@immortal:/images# xl restore tmp/c6-01.save
>> Loading new save file tmp/c6-01.save (new xl fmt info 0x3/0x0/950)
>> Savefile contains xl domain config in JSON format
>> Parsing config from <saved>
>> libxl: error: libxl_create.c:692:libxl__domain_make: Domain 19505:domain id 
>> recently used: No such
>> file or directory
>> libxl: error: libxl_create.c:1233:initiate_domain_create: Domain 
>> 19505:cannot make domain: -3
>> libxl: error: libxl_domain.c:1182:libxl__destroy_domid: Domain 
>> 19505:Non-existant domain
>> libxl: error: libxl_domain.c:1136:domain_destroy_callback: Domain 
>> 19505:Unable to destroy guest
>> libxl: error: libxl_domain.c:1063:domain_destroy_cb: Domain 
>> 19505:Destruction of domain failed
>> root@immortal:/images# xl restore tmp/c6-01.save
>> Loading new save file tmp/c6-01.save (new xl fmt info 0x3/0x0/950)
>> Savefile contains xl domain config in JSON format
>> Parsing config from <saved>
>> libxl: error: libxl_create.c:692:libxl__domain_make: Domain 19505:domain id 
>> recently used: No such
>> file or directory
>> libxl: error: libxl_create.c:1233:initiate_domain_create: Domain 
>> 19505:cannot make domain: -3
>> libxl: error: libxl_domain.c:1182:libxl__destroy_domid: Domain 
>> 19505:Non-existant domain
>> libxl: error: libxl_domain.c:1136:domain_destroy_callback: Domain 
>> 19505:Unable to destroy guest
>> libxl: error: libxl_domain.c:1063:domain_destroy_cb: Domain 
>> 19505:Destruction of domain failed
>> 
>> [A few minutes pass]
>> 
> 
> Yes, this is because it is not 'safe' to re-create the domain with the same 
> domid until it is deemed not 'recently used'. This
> should indeed be documented.

…and probably have a more informative error message. :-)

I can see why you wouldn’t want to start a *new* domain with a previous domain, 
but surely if you’re restoring the *same* domain, that check should be skipped?

 -George