(from the Windows Administrator's Guide, page 118) Increased Block Size for Writing to Tape
Tivoli Storage Manager provides a utility, DSMMAXSG, that can improve the rate at which the server processes data for backups and restores and for archives and retrieves. Actual results will depend upon your system environment. The utility does not affect the generation of backupsets. The utility increases the maximum transfer length for some Host Bus Adapters (HBAs) and, consequently, the block size used by the Tivoli Storage Manager server for writing data to and getting data from the following types of tape drives: --3570 --3590 --3592 --DLT --DTF --ECARTRIDGE --LTO The maximum supported block size with this utility is 256 KB. When you run DSMMAXSG, it modifies one registry key for every HBA driver on your system. The name of the key is MaximumSGList. Normally, the utility is executed automatically as part of the Tivoli Storage Manager server or storage agent installation. However, if you install a new HBA on your system after server or storage agent installation or if you install a new version of an existing HBA device driver that resets the value of the maximum transfer size, you must run the utility manually in order to take advantage of the larger block size. Note: If you back up or archive to tape using the 256 KB block size, you cannot append to or read from the tape using an HBA that does not support the 256 KB block size. For example, if you use a 256 KB Windows system for backing up client data to the Tivoli Storage Manager server, you cannot restore the data using a Windows system that supports a different transfer length. If you want to append to or read from tape written to using a 256 KB transfer length, you need to install an HBA that supports 256 KB transfers. For more information on the DSMMAXSG utility, see the Administrator's Reference. -- Mark Stapleton ([EMAIL PROTECTED]) Office 262.521.5627
