We are runnng SCCM 2007 R2 SP2 and the multicast DP is now running Server 2008 R2 64bit. The multicast DP was running Server 2008 but we upgraded it to R2 so we could make use of the automated disconnect of slow clients. The image wim is around 20GB and we are autocasting. Since upgrading we are having serious problems multicasting to new HP desktops (Probably about a 90% failure rate). Older hardware does not seem to suffer the same rate of failure (just the usual rate of failure of around 10%) . The image is "successfuly" downloaded to the machines but during extraction it detects a sparse part of the file and fails completely. If you keep trying the same machines it eventually works. We have tried the various suggestions for apblocksize and indeed slowed the stream to a crawl but it still fails in the same way. We have repeatedly tried diskpart-cleaning the disks but this doesn't help. Some of the interesting bits of the log file are shown below: <![LOG[MCS open session request completed successfully]LOG]!><time="11:11:07.979+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="mcsisapiclient.cpp:917"> <![LOG[Using MCSServer: MULTICASTSERVERNAME]LOG]!><time="11:11:07.979+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="mcsisapiclient.cpp:919"> <![LOG[Using Namespace: //multicastservername/SMSPKGF$/KN10020B]LOG]!><time="11:11:07.979+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="mcsisapiclient.cpp:920"> <![LOG[Using Encryption: FALSE]LOG]!><time="11:11:07.979+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="mcsisapiclient.cpp:921"> <![LOG[Session Start Time Delay:0]LOG]!><time="11:11:07.979+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="mcsisapiclient.cpp:922"> <![LOG[Using LocalPath: C:\_SMSTaskSequence\Packages\KN10020B]LOG]!><time="11:11:07.979+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="mcsisapiclient.cpp:923"> <![LOG[Opening firewall for X:\sms\bin\i386\OSDApplyOS.exe]LOG]!><time="11:11:07.979+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="mcclient.cpp:39"> <![LOG[Download: Server=MULTICASTSERVERNAME Namespace=//multicastservername/SMSPKGF$/KN10020B RemoteObject=\\multicastservername\SMSPKGF$\KN10020B\ LocalObject=C:\_SMSTaskSequence\Packages\KN10020B.{2B3C3104-2F38-46D8-8399-3BF882D69E6E}]LOG]!><time="11:11:07.995+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="968" file="mcdownload.cpp:102"> <![LOG[Checking volume for sparse files: C:\]LOG]!><time="11:11:07.995+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="968" file="fileutil.cpp:59"> <![LOG[Volume supports sparse files: TRUE]LOG]!><time="11:11:07.995+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="fileutil.cpp:74"> <![LOG[[SparseFile]]LOG]!><time="11:11:07.995+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="writefile.cpp:106"> <![LOG[Token before WdsTransportClientStartSession]LOG]!><time="11:11:07.995+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="mcdownload.cpp:170"> … <![LOG[Write File Progress [95]]LOG]!><time="11:39:18.694+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="780" file="mcdownload.cpp:299"> <![LOG[[Callback:SessionComplete:0x0]]LOG]!><time="11:40:52.357+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="1484" file="mcdownload.cpp:594"> <![LOG[[DownloadStatus:Status:2:Error:0]]LOG]!><time="11:40:52.357+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="mcdownload.cpp:204"> <![LOG[Progress: writedata 100/100]LOG]!><time="11:40:52.373+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="1520" file="resolvesource.cpp:2505"> <![LOG[Write File Progress [100]]LOG]!><time="11:40:52.373+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="1520" file="mcdownload.cpp:299"> <![LOG[Succesfully downloaded file]LOG]!><time="11:40:52.373+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="mcsisapiclient.cpp:1007"> <![LOG[Sending status message: SMS_OSDeployment_PackageDownloadMulticastStatusSuccess]LOG]!><time="11:40:52.373+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="mcsisapiclient.cpp:538"> <![LOG[Sending StatusMessage]LOG]!><time="11:40:52.404+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="libsmsmessaging.cpp:3806"> <![LOG[Formatted header:]LOG]!><time="11:40:52.404+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="libsmsmessaging.cpp:1500"> <![LOG[<Msg SchemaVersion="1.1" ReplyCompression="zlib"><ID/><SourceID>BA5F7D11-5D4B-4D89-9FA8-CEAB66FE5ABB</SourceID><SourceHost/><TargetAddress>mp:[http]MP_StatusManager</TargetAddress><ReplyTo>direct:OSD</ReplyTo><Priority>3</Priority><Timeout>3600</Timeout><SentTime>2011-08-24T10:40:52Z</SentTime><Protocol>http</Protocol><Body Type="ByteRange" Offset="0" Length="1330"/><Hooks/><Payload Type="inline"/><TargetHost/><TargetEndpoint>StatusReceiver</TargetEndpoint><ReplyMode>Sync</ReplyMode><CorrelationID/></Msg> ]LOG]!><time="11:40:52.404+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="libsmsmessaging.cpp:1501"> <![LOG[CLibSMSMessageWinHttpTransport::Send: URL: ROCHESTER.kent.ac.uk:80 CCM_POST /ccm_system/request]LOG]!><time="11:40:52.404+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="libsmsmessaging.cpp:7446"> <![LOG[The request has succeeded. 200 OK]LOG]!><time="11:40:52.435+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="968" file="libsmsmessaging.cpp:7734"> <![LOG[Checking volume for sparse files: C:\]LOG]!><time="11:40:52.435+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="968" file="fileutil.cpp:59"> <![LOG[Volume supports sparse files: TRUE]LOG]!><time="11:40:52.435+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="fileutil.cpp:74"> <![LOG[Opening file: C:\_SMSTaskSequence\Packages\KN10020B.{2B3C3104-2F38-46D8-8399-3BF882D69E6E} -> C:\_SMSTaskSequence\Packages\KN10020B]LOG]!><time="11:40:52.435+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="968" file="mcspacket.cpp:237"> <![LOG[Received header block for file:win7off2010spcprod.wim len=19825687278]LOG]!><time="11:40:52.435+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="mcspacket.cpp:516"> <![LOG[Progress: extract 0/100]LOG]!><time="11:40:52.435+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="968" file="resolvesource.cpp:2522"> <![LOG[Write Progress [1]]LOG]!><time="11:40:56.850+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="968" file="mcspacket.cpp:578"> … <![LOG[Write Progress [23]]LOG]!><time="11:43:21.103+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="968" file="mcspacket.cpp:578"> <![LOG[Found sparse part of the file: 4628414464 8192]LOG]!><time="11:43:21.743+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="968" file="mcspacket.cpp:285"> <![LOG[File not processed completely. Partial results may exist.]LOG]!><time="11:43:21.743+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="mcspacket.cpp:362"> <![LOG[Completed Extract File Succesfully]LOG]!><time="11:43:21.743+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="mcsisapiclient.cpp:1029"> <![LOG[Download done setting progress bar to 100]LOG]!><time="11:43:21.977+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="resolvesource.cpp:2598"> <![LOG[Succesfully performed multicast download from mcs://multicastservername/SMS_MCS/.sms_mcs?filePath=\\multicastservername\SMSPKGF$\KN10020B\&PackageFlags=202375168&packageID=KN10020B&version=4]LOG]!><time="11:43:21.977+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="resolvesource.cpp:2759"> <![LOG[Hash could not be matched for the downloded content. Original ContentHash = 185D32BBF5EADA2AB93D9346D42B201341676DFA, Downloaded ContentHash = 384F879EA3C94419ABA18F00DE9329CED7A08C95]LOG]!><time="11:43:57.904+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="3" thread="968" file="downloadcontent.cpp:1346"> <![LOG[0L == TS::Utility::VerifyPackageHash(pszContentID, sDestination), HRESULT=80091007 (e:\nts_sms_fre\sms\framework\tscore\resolvesource.cpp,2903)]LOG]!><time="11:43:57.904+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="968" file="resolvesource.cpp:2903"> <![LOG[DownloadContentAndVerifyHash(pszPackageID, L"SMSPackage", saHttpContentSources, saSMBContentSources, saMulticastContentSources, sDestination, dwFlags, L"", 0, dwPackageFlags, pszUserName, pszUserPassword ), HRESULT=80091007 (e:\nts_sms_fre\sms\framework\tscore\resolvesource.cpp,3002)]LOG]!><time="11:43:58.153+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="968" file="resolvesource.cpp:3002"> <![LOG[DownloadContentLocally(pszSource, sSourceDirectory, dwFlags, hUserToken, pszUserName, pszUserPassword), HRESULT=80091007 (e:\nts_sms_fre\sms\framework\tscore\resolvesource.cpp,3130)]LOG]!><time="11:43:58.153+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="968" file="resolvesource.cpp:3130"> <![LOG[ResolveSource(pszSource, sSourceDirectory, dwFlags, 0, 0, 0), HRESULT=80091007 (e:\nts_sms_fre\sms\framework\tscore\resolvesource.cpp,3031)]LOG]!><time="11:43:58.153+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="968" file="resolvesource.cpp:3031"> <![LOG[TS::Utility::ResolveSource( this->packageID, this->packagePath, TS::Utility::ResolveSourceFlags::PersistContents ), HRESULT=80091007 (e:\nts_sms_fre\sms\client\osdeployment\applyos\installimage.cpp,1354)]LOG]!><time="11:43:58.153+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="968" file="installimage.cpp:1354"> <![LOG[resolvePkgSource(), HRESULT=80091007 (e:\nts_sms_fre\sms\client\osdeployment\applyos\installimage.cpp,1396)]LOG]!><time="11:43:58.153+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="968" file="installimage.cpp:1396"> <![LOG[Apply(), HRESULT=80091007 (e:\nts_sms_fre\sms\client\osdeployment\applyos\installimage.cpp,1456)]LOG]!><time="11:43:58.153+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="968" file="installimage.cpp:1456"> <![LOG[Installation of image 1 in package KN10020B failed to complete.. The hash value is not correct. (Error: 80091007; Source: Windows)]LOG]!><time="11:43:58.153+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="3" thread="968" file="installimage.cpp:1476"> <![LOG[installer.install(), HRESULT=80091007 (e:\nts_sms_fre\sms\client\osdeployment\applyos\installimage.cpp,1527)]LOG]!><time="11:43:58.153+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="968" file="installimage.cpp:1527"> <![LOG[Entering ReleaseSource() for C:\_SMSTaskSequence\Packages\KN10020B]LOG]!><time="11:43:58.153+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="1" thread="968" file="resolvesource.cpp:3431"> <![LOG[The user tries to release a source directory C:\_SMSTaskSequence\Packages\KN10020B that is either already released or we have not connected to it]LOG]!><time="11:43:58.153+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="2" thread="968" file="resolvesource.cpp:3481"> <![LOG[InstallImage( g_InstallPackageID, g_ImageIndex, targetVolume, ImageType_OS, g_ConfigPackageID, g_ConfigFileName, bOEMMedia ), HRESULT=80091007 (e:\nts_sms_fre\sms\client\osdeployment\applyos\applyos.cpp,373)]LOG]!><time="11:43:58.153+-60" date="08-24-2011" component="ApplyOperatingSystem" context="" type="0" thread="968" file="applyos.cpp:373"> <![LOG[Process completed with exit code 2148077575]LOG]!><time="11:43:58.153+-60" date="08-24-2011" component="TSManager" context="" type="1" thread="992" file="commandline.cpp:1102"> Any thoughts greatly appreciated. I m just popping off to restart the failures, again! :-) Andy