Click here for the official IBM Fix Central search (Login required for download).
Because the IBM DS Series array family has reached End of Support (EOS) or End of Life (EOL) status, IBM has consolidated and moved many legacy drivers from its active primary portals into specific archival repositories. ibm ds storage manager 1086 download link
This is the primary repository for IBM software updates. You will need to search for "Disk Systems" and then select your specific model (e.g., DS3512) to see available Storage Manager versions. Click here for the official IBM Fix Central