VSS para os mais pequenos

Tirando um instantâneo - é aqui que qualquer backup começa. Até que saibamos como liberar todos os buffers para o disco e trazer os arquivos de dados para um estado consistente, não fazemos backups, mas copiamos arquivos com conteúdo imprevisível dentro. Compreendendo a importância dos snapshots, todos os fornecedores tentam nos dar, se não uma função completamente acabada (como o Time Mashine no MacOS), pelo menos um conjunto de botões que podem ser puxados (como o módulo dm-snap no kernel do Linux ) 





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Aqui está um ótimo exemplo: criamos um instantâneo em diskshadow e estamos tentando excluí-lo usando vssadmin.  Podemos ver a imagem em si, mas não está em nosso contexto, portanto, está desarrumada, não temos força aqui.
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PS C:\Windows\system32> diskshadow
Microsoft DiskShadow version 1.0
Copyright (C) 2013 Microsoft Corporation
On computer:  VEEAM,  17.05.2021 19:18:44

DISKSHADOW> add volume c: #     

DISKSHADOW> create	#  
Alias VSS_SHADOW_1 for shadow ID {a1eef71e-247e-4580-99bc-ee62c42221d6} set as environment variable.
Alias VSS_SHADOW_SET for shadow set ID {cc9fab4d-3e7d-44a5-9a4d-0df11dd7219c} set as environment variable.

Querying all shadow copies with the shadow copy set ID {cc9fab4d-3e7d-44a5-9a4d-0df11dd7219c}

        * Shadow copy ID = {a1eef71e-247e-4580-99bc-ee62c42221d6}               %VSS_SHADOW_1%
                - Shadow copy set: {cc9fab4d-3e7d-44a5-9a4d-0df11dd7219c}       %VSS_SHADOW_SET%
                - Original count of shadow copies = 1
                - Original volume name: \\?\Volume{7fd0c79d-0000-0000-0000-602200000000}\ [C:\]
                - Creation time: 17.05.2021 19:19:45
                - Shadow copy device name: \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy2
                - Originating machine: veeam.university.veeam.local
                - Service machine: veeam.university.veeam.local
                - Not exposed
                - Provider ID: {b5946137-7b9f-4925-af80-51abd60b20d5}
                - Attributes:  Auto_Release Differential

Number of shadow copies listed: 1

      
      



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DISKSHADOW> expose {a1eef71e-247e-4580-99bc-ee62c42221d6} Z:
The shadow copy is a non-persistent shadow copy. Only persistent shadow copies can be exposed.

      
      



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DISKSHADOW> delete shadows all #    ID
Deleting shadow copy {a1eef71e-247e-4580-99bc-ee62c42221d6} on volume \\?\Volume{7fd0c79d-0000-0000-0000-602200000000}\ from provider {b5946137-7b9f-4925-af80-51abd60b20d5} [Attributes: 0x00420000]...

Number of shadow copies deleted: 1
      
      



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DISKSHADOW> add volume C:

DISKSHADOW> set context persistent #   

DISKSHADOW> create
Alias VSS_SHADOW_1 for shadow ID {346d896b-8722-4c01-bf01-0f38b9abe20a} set as environment variable.
Alias VSS_SHADOW_SET for shadow set ID {785983be-e09d-4d2a-b8b7-a4f722899896} set as environment variable.

Querying all shadow copies with the shadow copy set ID {785983be-e09d-4d2a-b8b7-a4f722899896}

        * Shadow copy ID = {346d896b-8722-4c01-bf01-0f38b9abe20a}               %VSS_SHADOW_1%
                - Shadow copy set: {785983be-e09d-4d2a-b8b7-a4f722899896}       %VSS_SHADOW_SET%
                - Original count of shadow copies = 1
                - Original volume name: \\?\Volume{7fd0c79d-0000-0000-0000-602200000000}\ [C:\]
                - Creation time: 17.05.2021 19:38:45
                - Shadow copy device name: \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy3
                - Originating machine: veeam.university.veeam.local
                - Service machine: veeam.university.veeam.local
                - Not exposed
                - Provider ID: {b5946137-7b9f-4925-af80-51abd60b20d5}
                - Attributes:  No_Auto_Release Persistent Differential

Number of shadow copies listed: 1
      
      



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