Virtual restore creates big log files with "Crc mismatch"

james1248james1248 Posts: 3
edited July 23, 2011 6:01PM in SQL Virtual Restore 2
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

Comments

  • Is the backup file a SQB, HyperBac or Native backup? What is the version info from the service.log file?
    Jeffrey Aven
    Product Management - HyperBac Technologies
    Red Gate Software
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