>Is TSM planning on adding data deduplication similar to avamar? As mentioned by Richard, the closest thing TSM has to this now is subfile backup. It is related to de-duplication, where once it has a backup of a given file, it backs up only the changed bytes of that file. This is also referred to as delta incrementals.
True de-duplication takes this much farther, as it would recognize a file or email that's duplicated on two or three different systems, such as an attachment/email that's sent to users on several different Exchange servers. The "compression" ratios it can achieve are therefore much higher than delta differentials. >I understand how TSM does not duplicate data now but minor edits in files >or simple file name changes would result in additional copies of the >entire file using TSM today. Instead of switching from TSM to something like Avamar (EMC) or Puredisk (Symantec), a TSM user can benefit from de-dupe today by using a de-duplication backup target, such as de-dupe VTL or NAS device. Just make sure you realize that you won't the same de-dupe as non-TSM users. (TSM customers who switch to a de-dupe target are seeing approximately 10:1 de-dupe ratios, where non-TSM customers are seeing 20:1.) Most TSM users don't do repeated full backups of their filesystems, and a lot of the duplicated data comes from those full backups. But TSM users still have duplicated data: multiple versions of the same file and database backups. You already mentioned edited versions of the same file. It is also common that a file will be present in multiple places. In addition, TSM users do perform periodic full backups of their database data. >We recently had a pitch from EMC on avamar. I can think of some reasons >to pass on it (Having two separate backup/restore solutions is a big >one, cost etc) but some persuasive arguments were made supporting their >solution. If you like the idea of using de-dupe to backup your remote offices (which is what Avamar and Puredisk are designed for), but want to stay with TSM, again de-dupe targets can help. Buy a small de-dupe target to place at your remote site, perform TSM backups to it, then replicate the new/unique blocks to a central location as your offsite mechanism. >If TSM is going to be adding similar functionality soon it may >be another reason to focus on other efforts. Writing a de-dupe backup product isn't easy. EMC bought Avamar and Symantec bought Data Center Technologies to get their respective products. I don't know of any other de-dupe companies for IBM to acquire, so they'll have to write their own. That may take them a bit longer.
