You can manually tell it what drive to store content on see SS: Justin Chalfant | Blog: setupconfigmgr.com | SCUP Catalog: patchmypc.net/scup | Please mark as helpful/answer if this resovled your issue

I had a question regarding package location if anyone can answer. For example if you have the site server with 3 drives C,D,E 50,100,200 respectively. I have noticed that sccm will automatically pick the drive with the largest disk space to place its packages. Is this function default in sccm 2007? Is there a way to specify which drive to put its packages? Same goes for secondary sites. Any help in the matter would be appreciated.

You can manually tell it what drive to store content on see SS: Justin Chalfant | Blog: setupconfigmgr.com | SCUP Catalog: patchmypc.net/scup | Please mark as helpful/answer if this resovled your issue

The "Location of stored packages" option only controls where the compressed form of the packages (in the form of PCK files) are stored when they are copied between sites. For the actual uncompressed source folders presented to clients via the SMSPKGx$ folders/shares, it will also pick the largest volume available each and every time a package is deployed to a DP. The only way to control this is no placing an empty file name no_sms_on_drive.sms file in the root of the volume you do not want ConfigMgr to use. Ideally, this file should be on those volumes before you install the system as a DP (or any other site system), but I think it can be made to take these files into consideration by restarting the SMS services also.Jason | http://blog.configmgrftw.com