Virtual restore creates big log files with "Crc mismatch"

james1248

Hi,

Trialing Virtual Restore and found it to be x4 slower than normal restore at times. Have noticed that virtual restore creates huge log files, writing a few lines every millisecond about "Crc mismatches" - which is probably why it's so slow. The file I'm restoring is about 130GB.

Is it a problem with the backup file?

Here's an extract and this repeats hundreds of thousand times. The restore finishes eventually and all integrity checks run afterwards are OK.

*******************************************************************
*
* 20 Jul 11 12:46:22.294 OPENED LOG FILE
*
HyperFile=000000000FC19DC0
FileName=********.vmdf
OpenTime=Wed Jul 20 12:46:10 2011
OpenProcessId=5232
OpenProcessName=\Device\HarddiskVolume4\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\Binn\sqlservr.exe
ProcessAttr1=0
ProcessAttr2=0
IndexNumber=0x143000000000038
HeaderVersion=2
FileType=1
FormatVersion=0x3
CreateVersion=0x5020107
CreateOS=0x10600
FileFlags=0xB8
RequiredVersion=0x3
WriteAccess=Yes
FillFactor=118272
VirtualEOF=0xA96D00000
FileActualStart=0x400
FileActualEnd=0x20000
LastDataBlock=0x20000
FileActualMetaEnd=0x0
LastCrcOffset=0xA96D00000
SequentialOffset=0xA96D00000
LastBlockOffset=0xA96D00000
IndexType4Format=1
IndexStart=0x20000
IndexEnd=0x0
OpenHandleCount=1
FileDirty=Yes
IoError=0
UpdateCount=0x4
LastIoOffset=0x0
ActiveWrites=8
FileState=0x0
LastSumOffset=0x0
AffinityMask=0xFFFFFFFFFFFFFFFF
*
*******************************************************************

20 Jul 11 12:46:22.294 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x0.
20 Jul 11 12:46:22.299 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x0.
20 Jul 11 12:46:22.300 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x0.
20 Jul 11 12:46:22.301 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x0.
20 Jul 11 12:46:22.302 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x0.
20 Jul 11 12:46:22.303 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x0.
20 Jul 11 12:46:22.305 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x10000.
20 Jul 11 12:46:22.306 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x10000.
20 Jul 11 12:46:22.308 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x10000.
20 Jul 11 12:46:22.309 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x10000.
20 Jul 11 12:46:22.310 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x10000.
20 Jul 11 12:46:22.312 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x10000.
20 Jul 11 12:46:22.313 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x10000.
20 Jul 11 12:46:22.314 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x20000.
20 Jul 11 12:46:22.314 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x20000.
20 Jul 11 12:46:22.375 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x20000.
20 Jul 11 12:46:22.376 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x20000.
20 Jul 11 12:46:22.378 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x20000.
20 Jul 11 12:46:22.379 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x30000.
20 Jul 11 12:46:22.380 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x30000.
20 Jul 11 12:46:22.381 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x30000.
20 Jul 11 12:46:22.382 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x30000.
20 Jul 11 12:46:22.383 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x30000.
20 Jul 11 12:46:22.384 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x40000.
20 Jul 11 12:46:22.385 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x40000.
20 Jul 11 12:46:22.386 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x40000.
20 Jul 11 12:46:22.387 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x50000.
20 Jul 11 12:46:22.388 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x50000.
20 Jul 11 12:46:22.389 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x50000.
20 Jul 11 12:46:22.391 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x50000.
20 Jul 11 12:46:22.392 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x60000.
20 Jul 11 12:46:22.429 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x60000.
20 Jul 11 12:46:22.430 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x60000.
20 Jul 11 12:46:22.431 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x60000.
20 Jul 11 12:46:22.432 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x70000.
20 Jul 11 12:46:22.433 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x70000.
20 Jul 11 12:46:22.434 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x70000.
20 Jul 11 12:46:22.435 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x70000.
20 Jul 11 12:46:22.436 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x80000.
20 Jul 11 12:46:22.437 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x80000.
20 Jul 11 12:46:22.438 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x80000.
20 Jul 11 12:46:22.439 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x80000.
20 Jul 11 12:46:22.440 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x80000.
20 Jul 11 12:46:22.441 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x80000.
20 Jul 11 12:46:22.442 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x90000.
20 Jul 11 12:46:22.443 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x90000.
20 Jul 11 12:46:22.444 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x90000.
20 Jul 11 12:46:22.491 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0x90000.
20 Jul 11 12:46:22.492 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0xA0000.
20 Jul 11 12:46:22.493 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0xA0000.
20 Jul 11 12:46:22.495 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0xA0000.
20 Jul 11 12:46:22.496 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0xB0000.
20 Jul 11 12:46:22.497 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0xB0000.
20 Jul 11 12:46:22.498 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0xB0000.
20 Jul 11 12:46:22.499 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0xB0000.
20 Jul 11 12:46:22.500 CheckMtfBlock: FileRecord: 000000000FC19DC0, Crc mismatch on firstCrcInfo->Offset: 0xC0000.
... and repeats +1million times.

Cheers
James

javen

Is the backup file a SQB, HyperBac or Native backup? What is the version info from the service.log file?