I am going to revisit the issue of backup, cost, and the total cost of ownership of backup in this post. Tony Pearson and I have been discussing this (hopefully in a fairly constructive fashion) over the last little while, and I see he has responded to some of the points that I made in my previous post on the issue. Tony's response can be found here: "The TCO of TSM for Backup".
Tony continues to maintain (I think) that TSM has a "good" TCO and is efficient relative to other backup applications. Although I don't agree with a lot of what he writes, I do think that there are some pretty good lessons to be learned amidst the information he has posted, so I am going to continue to pursue this a bit in this post.
First, Tony claims that I said "only the cost of new TSM servers should be considered in any comparison." Ummm, jeepers Tony, no I didn't! I would never make any such claim! (What I did say is that TSM is unique in the backup world, in that it scales by adding master servers. Once my TSM master server is at capacity, due to I/O requirements, or database scale, or ability to drive disk or tape, I have to buy another master. That stands in sharp contrast to Networker or Netbackup, where I can just buy a Storage Node or Media Server--which tend to be much smaller systems with much less disk than the master servers. So TSM requires many more master servers than competitive solutions--each of which imposes not just a burden of cost, but a management burden at both the server level and the backup application level. Further, based on my experience, the typical TSM customer will end up with more master servers than they would have combined master and media servers if they were using Netbackup or Networker.)
Servers are but one of many cost considerations when it comes to understanding the TCO of a backup environment. Generally speaking, these costs can be divided into hard and soft costs. Hard costs are costs associated with physical, tangible things (servers, network, disk, tape drives, shipping, etc.). Soft costs are those costs associated with stuff that is less tangible. Soft costs can include labor and administration--though truthfully admin costs straddle the line between hard and soft costs, at least in part because they can be difficult to accurately quantify--but also include things like risk, efficiency, and the benefit of systems uptime.
