zhangfred_vm
Contributor
Contributor

What's the detailed process to create the snapshot for virtual machine

Hi experts,

What's the detailed process to create the snapshot for virtual machine, where is the snapshot file?

The VI client send command to VC to create the snapshot? the VC quiese the file system>

thanks

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5 Replies
kjb007
Immortal
Immortal

Not sure how detailed you want, but below is overview

VI Client talks to vc and requests snapshot of a vm.

vc talks to esx host, and requests vm snapshot

vm creates delta file, and stops writing to current disk

if memory is also requested, and the vm is up, then memory and state is written to disk

all new writes are written to delta file, and memory processes as usual

-KjB

vExpert/VCP/VCAP vmwise.com / @vmwise -KjB
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Chris_Howard
Hot Shot
Hot Shot

Hi,

there is some excellent detail on how snapshots work at the searchvmware.com website here and here .

Regards,

Chris.

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zhangfred_vm
Contributor
Contributor

Thanks for you help, the below is my question.

1. Does it need we add the virtual machine one by one when we use vcb with the the veritas.

2. what is the snapshot file?

does the below files belong to the snapshot file?

VM_2003-Snapshot5.vmsn

VM_2003-000003-delta.vmd

VM_2003-000003.vmdk

3. when the vcbbackup is complished.

Will the the snapshot file be removed and any changes are rewrite to the original vmdk fils?

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deepak_ashwath
VMware Employee
VMware Employee

Hi Zhangfred,

the snapshot file just stores the "state of the virtual machine"...

Right click on a VM... and click "Take Snapshot"-which stores the state of the virtual machine ...

if you want to restore to the old state of the VM.... click "Revert to Snapshot" then it actually refers to vmsn and vmsd files to get back the state of the VM.

these files are used for VMware snapshots. A VMSN file is used to store the exact state of the virtual machine when the snapshot was taken. Using this snapshot, you can then restore your machine to the same state as when the snapshot was taken. A VMSD file stores information about snapshots (metadata). You'll notice that the names of these files match the names of the snapshots.

No much idea on VCB

Regards,

Deepak Ashwath

kjb007
Immortal
Immortal

1. Not sure if you need to do it one at a time, or if you can do a bulk load, but you want the vcb backup to be referenced by the VM name, and not by the vcb proxy name. Veritas is pretty good with that, and I believe they have a whitepaper on how to set that up, but I don't have a link for you.

2. The snapshot file is the .vmsn file. The -delta.vmdk file is the new writes since the snapshot file was taken. The .vmdk file is a descriptor file that contains the metadata to represent the -delta.vmdk file.

3. When VCB completes, the snapshot is supposed to go away.

-KjB

vExpert/VCP/VCAP vmwise.com / @vmwise -KjB