In the system Event log we see:
“The shadow copies of volume D: were aborted because the shadow copy storage could not grow due to a user imposed limit”
From binary log:
Error 2015/03/05 16:39:48 70 Data Plugin HOST01 Failed to backup VM VMFS01
Error 2015/03/05 17:07:49 70 Data Plugin HOST01 Failed to backup VM VMVAULT
Hyper-V trace extract
0 FILESYS ??? 3688 6 21 170742514793 Failed to read: The device is not ready.
0 HV_BU ??? 3688 23 0 170742514793 Failed to read from file d:\hyperv_apm_working_dir\vmvault\im\vss_expose\\d\hyperv\vmvault01\vmvault-d.vhdx
0 VSSBACK ??? 3688 118 0 170749776714 Problem deleting snapshots, 0 snapshots remaining
0 VSSBACK ??? 3688 119 0 170749776714 Failed with error -2147212536
0 HV_BU ??? 3688 35 0 170749777715 MAS cleanup workingdir D:\HyperV_APM_Working_Dir
2 HV_UTIL ??? 3688 50 0 170749777715 Attempt deleting file '\\?\D:\HyperV_APM_Working_Dir\VMVAULT\im\bkbtemp\recover_ctx.dat'
0 HV_UTIL ??? 3688 47 0 170749778713 Directory \\?\D:\HyperV_APM_Working_Dir\VMVAULT\im\vss_expose\D cannot be opened
Insufficient space allocated on the snapshots on snapshot volume.
List the shadow storage with following command:
vssadmin List ShadowStorage
Below is sample output showing that 17 GB of 20 GB maximum space is being used by VSS shadow copies on a volume, we would recommend that the maximum size value be increased.
Used Shadow Copy Storage space: 17.053 GB (22%)
Allocated Shadow Copy Storage space: 18.02 GB (24%)
Maximum Shadow Copy Storage space: 20 GB (26%)
If the OS's current Shadow Copy settings seem to be too small, that limit can be increased by using the following Windows command:
vssadmin Resize ShadowStorage
It may be necessary to use the following command that gives the VSS unlimited use of space on the snapshot volume as the snapshots size will change when snapshotting different VM’s. in the example below we have modified the d:\ drive
vssadmin resize shadowstorage /For=D: /On=D: /MaxSize=unbound
In order to do the resize, please follow Microsoft's recommendations on the following Microsoft TechNet KB article:
http://technet.microsoft.com/en-us/library/cc788050.aspx
Note: This issue is strictly a Windows issue and in no way NetVault-related.
