Many times when deploying an operating system using SCCM, the task sequence fails on the client. Most of the time, the error presented on the screen does not provide sufficient information to determine what’s failing. This is when you need to look at the logs created by the deployment.
If you have enabled command support on your boot image, you can press F8 if the task sequence failed while in Windows PE to gain access to a command prompt. You enable command support in the Windows PE tab of the boot image properties.
Once at the command prompt, you can look for log files. Their location may be tricky as they move around as the deployment progresses. For example, the smsts.log file is
- At x:\windows\temp\smstslog in Windows PE before the hard disk is formatted (x: is a RAM drive)
- At x:\smstslog after the disk is formatted
- At c:\_SMSTaskSequence\Logs\SMStslog after the disk is formatted
Another important log to analyze is the bdd.log. This log contains a summarized view of all other MDT log files. If it is difficult in your particular scenario to have access to the target machine to press F8 and gain access to a command prompt while in Windows PE, the machine will restart and the logs will be gone. Although it is possible to configure your deployment so the log files are copied to a network share when the task sequence completes, sometimes a failure may prevent the task sequence from reaching the step at the end with instructions to copy the files. The following entry in your CustomSettings.ini file will copy the logs to the specified share.
SLShare=\\<serverName>\<shareName>\%OSDComputerName%
In this case, the logs will be copied to a folder in the share named after the target computer name.
When working a difficult issue with your deployment, it may be necessary to enable real time logging over the network. If you add the instruction below to your CustomSettings.ini file, real time logging is performed on the bdd.log file on the specified share location, in addition of logging on the target computer locally. If you open the file with the Configuration Manager Toolkit utility trace32.exe, you can view the entries being added to the log.
SLShareDynamicLogging=\\<serverName>\<shareName>\%OSDComputerName%
Once you have fixed your challenging issue, disable this dynamic logging over the network. There’s a substantial amount of network traffic generated as every line logged requires the file to be open, the line to be written to it, and the file to be closed.
