how to move an ECS to a different VS in the same region - Alibaba Cloud Developer Forums: Cloud Discussion Forums

moralest
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[Others]how to move an ECS to a different VS in the same region

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More Posted time:May 23, 2018 21:05 PM
Hi all


I am trying to move some ECS from one VS to a different VS in the same VPC. I am trying to 'remove link to VPC' but it doesn work. Is this possible?


Thanks

moralest
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1st Reply#
Posted time:May 23, 2018 21:10 PM
sorry, it is not in the same VPC. I am trying to move ECS between VPCs in the same region

abdulhafeez
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2nd Reply#
Posted time:May 26, 2018 5:18 AM
You can achieve this by this workaround.

1. Take image of ECS (create image from instance with all disks)
2. Once image is taken 100%. Shutdown the ECS.
3. Create new ECS instance in other VS in other VPC (it will have different IP from that VS range)
4. Check if every thing is fine.
5. You can release the original ECS that was shut down.

JohnHanley
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3rd Reply#
Posted time:May 26, 2018 18:10 PM
Shutdown the ECS instance first, then create an image. You do not want to create an image of a running system.

abdulhafeez
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4Floor#
Posted time:May 30, 2018 13:52 PM
Instance image can be created without shutting down the ECS. No need to shutdwown ECS to take the image.. this will avoid unnecessary outage of the server/application.

JohnHanley
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5Floor#
Posted time:May 31, 2018 1:34 AM
If you image a running system you risk inconsistent images. This is caused by the operating system caching file system and application data in memory that is not part of the image.

If you have specific knowledge about how Alibaba does this differently share the link. I have spent more than 25 years working for storage companies writing software that image / snapshot / backup  systems.

Both Linux and Windows have drivers for snapshotting the system. However, this requires 100% of the operating system and applications to participate in the freeze / thaw cycle. In the real world few applications do so.

Even AWS and Azure have a button to reboot the instance during the image creation. There is a reason why they recommend shutting down the system to take an image - inconsistent images.

abdulhafeez
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6Floor#
Posted time:Jun 4, 2018 18:10 PM
I have taken ECS image multiple times without shutting down the ECS, Infact I deleted original instance and created new instance from custom image without any loss of data !!


If you create custom image from instance (properties page inside the instance where you see instance information..more..create custom image). It will create snapshot of each disk first (system disk + data disks), then it will create image from system disk. That is automatic process.


If you have any doubt, I can offer you a free remote session to give you demo on same to prove my point :)


Cheers.
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