> Deduplicating VTLs fit better into NBU sites. TSM's progressive > incremental methodology already reduces the data stream, making deduping > VTLs less of a "win", though it can still be beneficial.
As I've said before, TSM's progressive incremental does tend to reduce the total dedupe ratio by about 50% (from an average of 20:1 to 10:1). There is still plenty of duplicate data between the multiple versions of each file you're saving in TSM, and TDP backups stil do fulls and incrementals. > My point is that > VTL vendors may not look as positively on TSM as they do on other > less-efficient backup solutions, because they don't sell as much VTL > product to them. IMHO. This is DEFINITELY not the case, as most VTL vendors that I've talked to are selling a disproportionate amount of VTLs on TSM. In fact, I'm seeing more customers than I thought I would abandoning their disk pool and going straight to VTL. When we start talking dedupe, though, the numbers do go way down, though. There's no doubt it brings a benefit to the TSM customer, but the pricing is such that some TSM customers feel they're being overcharged. If dedupe makes my 1 TB array look like a 10 TB array (10:1 dedupe, common with TSM), and you want to charge me a 10x multiple for it, what's the point in that? (I'm not saying that's how the vendors are pricing it. I'm just giving an example of the type of pricing that might turn off a TSM customer.) --- W. Curtis Preston Backup Blog @ www.backupcentral.com VP Data Protection, GlassHouse Technologies This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail.