How to resolve the backup error 'Insufficient Storage Space'

How to resolve the backup error 'Insufficient Storage Space'

Introduction

VSS (Volume Shadow Copy Service) is a feature within the Microsoft Windows OS (operating system) that allows applications to take a "point-in-time snapshot" of an entire storage volume without locking the filesystem. If there is not enough free space on the VSS storage, a backup may fail with the following error:
The system or provider has insufficient storage space. If possible delete any old or unnecessary persistent shadow copies and try again.

In this article, we will walk through how to verify the current VSS storage allocation and adjust the VSS storage in order to resolve the error. 
In order to resolve this error, you can either expand the VSS shadow storage or delete VSS shadow copies from the current storage to free space.

Instructions

How to verify the current VSS storage allocation

1) Click on the Start menu button (i.e., the Windows flag icon in the lower-left corner):
2) Type "cmd" to search for the Command Prompt application:
3) Right-click on Command Prompt and select Run as administrator:
4) Check the size of the VSS shadow copy storage with the following command:
  1. C:\> vssadmin list shadowstorage
For additional information about the command used above, please review the article vssadmin list shadowstorage from Microsoft.

Sample Output:
  1. vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
  2. (C) Copyright 2001-2013 Microsoft Corp.

  4. Shadow Copy Storage association
  5.       For volume: (C:)\\?\Volume{55ce9f76-2c16-4b08-b03a-621373750a9d}\
  6.       Shadow Copy Storage volume: (C:)\\?\Volume{55ce9f76-2c16-4b08-b03a-621373750a9d}\
  7.       Used Shadow Copy Storage space: 10.2 GB (9%)
  8.       Allocated Shadow Copy Storage space: 10.7 GB (9%)
  9.       Maximum Shadow Copy Storage space: 11.1 GB (10%)
The number of disks, their names, and the amount of free space on your system will vary from the output above. In this particular scenario, the output shows that the shadow storage is full. 

How to expand the VSS shadow copy storage

1) Run the following command in the Windows command prompt in order to expand the VSS shadow storage:
Set the drive letter (e.g., C:) to the Shadow Copy Storage volume on your system.
  1. C:\> vssadmin resize shadowstorage /For=C: /On=C: /MaxSize=UNBOUNDED
For additional information about the command used above, please review the article vssadmin resize shadowstorage from Microsoft.

Sample Output:
  1. vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
  2. (C) Copyright 2001-2013 Microsoft Corp.

  4. Successfully resized the shadow copy storage association

2) Verify the expansion with the following command:
  1. C:\> vssadmin list shadowstorage

Sample Output:
  1. vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
  2. (C) Copyright 2001-2013 Microsoft Corp.

  4. Shadow Copy Storage association
  5.       For volume: (C:)\\?\Volume{55ce9f76-2c16-4b08-b03a-621373750a9d}\
  6.       Shadow Copy Storage volume: (C:)\\?\Volume{55ce9f76-2c16-4b08-b03a-621373750a9d}\
  7.       Used Shadow Copy Storage space: 10.2 GB (9%)
  8.       Allocated Shadow Copy Storage space: 10.7 GB (9%)
  9.       Maximum Shadow Copy Storage space: UNBOUNDED (3623414811%)

How to delete VSS shadow copies from the VSS shadow storage

This approach is NOT recommended and should only be used if expanding fails to resolve the issue or is impossible due to insufficient space.

1) Run the following command to delete the VSS shadow copies from the storage. You will be asked to confirm the deletion:
Set the drive letter (e.g., C:) to the Shadow Copy Storage volume on your system
  1. C:\> vssadmin delete shadows /for=C: /all
For additional information about the command used above, please review the article vssadmin delete shadowstorage from Microsoft.

Sample Output:
  1. vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
  2. (C) Copyright 2001-2013 Microsoft Corp.

  4. Do you really want to delete [X] shadow copies (Y/N): [N]? y

  6. Successfully deleted [X] shadow copies.

2) Verify the deletion with the following command:
  1. C:\> vssadmin list shadowstorage

Sample Output:
  1. vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
  2. (C) Copyright 2001-2013 Microsoft Corp.

  4. Shadow Copy Storage association
  5.       For volume: (C:)\\?\Volume{55ce9f76-2c16-4b08-b03a-621373750a9d}\
  6.       Shadow Copy Storage volume: (C:)\\?\Volume{55ce9f76-2c16-4b08-b03a-621373750a9d}\
  7.       Used Shadow Copy Storage space: 0 bytes (0%)
  8.       Allocated Shadow Copy Storage space: 0 bytes (0%)
  9.       Maximum Shadow Copy Storage space: UNBOUNDED (3623414811%)