I thought I’d do a series of posts over time about little known or unknown features of backup software. First up is TSM and its storage agent feature.
A lot of people think that TSM has only a two-tier architecture. That is, you have TSM clients and TSM servers. They believe that TSM has no equivalent to a NetBackup media server or a NetWorker storage node. While a TSM storage agent is not a full equivalent to a media server/storage node, it does more than people realize. This means that TSM has a three-tier architecture.
You can install the storage agent on any TSM client that is connected to storage resources (tape/disk/VTL). That will then allow that client to back up its data LAN-free directly to those resources, while having its backups tracked by the TSM server. Although LAN-free backups are not as commonplace in TSM environments as they are in other environments, there are quite a people using them, based on the level of traffic I see on the TSM mailing list talking about them.
The part that most people don’t know, though, is that clients running the TSM storage agent can actually back up other clients as well. IN the dsm.sys file on the client without the storage agent, you specify TCP/IP as your LANFREECOMMMETHOD, and for LANFREETCPSERVERADDRESS you specify the IP address of the client with the storage agent. The client without the storage agent would then back its data up over IP to the client with the storage agent, and the client with the storage agent would transfer that data via the SAN to disk or tape. This is very rare for TSM customers to use this feature, but at least one person on the TSM mailing list verified that it works as advertised.
In order to back up to disk, IBM does require you to use the SANergy product, but a license for that product is included with the software. Unfortunately, one user’s opinion about how well SANergy works was not very complimentary, so you’ll have to be the judge of whether or not that will work for you. You can also use a VTL if you want to back up to disk.
So there you have it, my first installment in the Unknown Features series.