Re: [Xen-devel] XCP: sr driver question wrt vm-migrate

[yamamoto@xxxxxxxxxxxxx (YAMAMOTO Takashi)]

hi,

thanks.  i'll take a look at the log if it happens again.

YAMAMOTO Takashi

> This is usually the result of a failure earier on. Could you grep through the 
> logs to get the whole trace of what went on? Best thing to do is grep for 
> VM.pool_migrate, then find the task reference (the hex string beginning with 
> 'R:' immediately after the 'VM.pool_migrate') and grep for this string in the 
> logs on both the source and destination machines. 
> 
> Have a look  through these, and if it's still not obvious what went wrong, 
> post them to the list and we can have a look.
> 
> Cheers,
> 
> Jon
> 
> 
> On 16 Jun 2010, at 07:19, YAMAMOTO Takashi wrote:
> 
>> hi,
>> 
>> after making my sr driver defer the attach operation as you suggested,
>> i got migration work.  thanks!
>> 
>> however, when repeating live migration between two hosts for testing,
>> i got the following error.  it doesn't seem so reproducable.
>> do you have any idea?
>> 
>> YAMAMOTO Takashi
>> 
>> + xe vm-migrate live=true uuid=23ecfa58-aa30-ea6a-f9fe-7cb2a5487592 
>> host=67b8b07b-8c50-4677-a511-beb196ea766f
>> An error occurred during the migration process.
>> vm: 23ecfa58-aa30-ea6a-f9fe-7cb2a5487592 (CentOS53x64-1)
>> source: eea41bdd-d2ce-4a9a-bc51-1ca286320296 (s6)
>> destination: 67b8b07b-8c50-4677-a511-beb196ea766f (s1)
>> msg: Caught exception INTERNAL_ERROR: [ 
>> Xapi_vm_migrate.Remote_failed("unmarshalling result code from remote") ] at 
>> last minute during migration
>> 
>>> hi,
>>> 
>>> i'll try deferring the attach operation to vdi_activate.
>>> thanks!
>>> 
>>> YAMAMOTO Takashi
>>> 
>>>> Yup, vdi activate is the way forward.
>>>> 
>>>> If you advertise VDI_ACTIVATE and VDI_DEACTIVATE in the 'get_driver_info' 
>>>> response, xapi will call the following during the start-migrate-shutdown 
>>>> lifecycle:
>>>> 
>>>> VM start:
>>>> 
>>>> host A: VDI.attach
>>>> host A: VDI.activate
>>>> 
>>>> VM migrate:
>>>> 
>>>> host B: VDI.attach
>>>> 
>>>>  (VM pauses on host A)
>>>> 
>>>> host A: VDI.deactivate
>>>> host B: VDI.activate
>>>> 
>>>>  (VM unpauses on host B)
>>>> 
>>>> host A: VDI.detach
>>>> 
>>>> VM shutdown:
>>>> 
>>>> host B: VDI.deactivate
>>>> host B: VDI.detach
>>>> 
>>>> so the disk is never activated on both hosts at once, but it does still go 
>>>> through a period when it is attached to both hosts at once. So you could, 
>>>> for example, check that the disk *could* be attached on the vdi_attach 
>>>> SMAPI call, and actually attach it properly on the vdi_activate call.
>>>> 
>>>> Hope this helps,
>>>> 
>>>> Jon
>>>> 
>>>> 
>>>> On 7 Jun 2010, at 09:26, YAMAMOTO Takashi wrote:
>>>> 
>>>>> hi,
>>>>> 
>>>>> on vm-migrate, xapi attaches a vdi on the migrate-to host
>>>>> before detaching it on the migrate-from host.
>>>>> unfortunately it doesn't work for our product, which doesn't
>>>>> provide a way to attach a volume to multiple hosts at the same time.
>>>>> is VDI_ACTIVATE something what i can use as a workaround?
>>>>> or any other suggestions?
>>>>> 
>>>>> YAMAMOTO Takashi
>>>>> 
>>>>> _______________________________________________
>>>>> Xen-devel mailing list
>>>>> Xen-devel@xxxxxxxxxxxxxxxxxxx
>>>>> http://lists.xensource.com/xen-devel
>>>> 
>>>> 
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>>> 
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> 
> 
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