> I a dedup appliance, that is exactly what you don't have. The dedup > process guarantees that only one copy is kept of each unique block of > that data. If a given block of data is lost due to corruption or > failure of the media, then potentially all of the copies of a certain > file that contains that block of data will be lost. The people who are > designing these products, therefore, build their products to mitigate > this potential loss by:
This is exactly what scares me about dedup - the unit of recovery. For our current (and foreseeable future) tape systems, the unit of loss and recover is a TAPE. With a VTL/dedup it's a much larger unit which is hard to define, but could be up to the entire appliance. A software bug could potentially take out not only a local appliance, but a replication target. When DataDomain was here a few weeks ago, I asked them if they have ever had a data loss event. They quickly replied "NO". I wish I knew whether to believe them - vendors do NOT like to acknowledge crashed systems. Another question I asked - Why would I EVERY have to take your system down? Their reply what that it takes about 2hr to perform a microcode load. Other than that, it should never have to come down. That then leads to a discussion of frequence of code releases and how quickly one must upgrade. (I don't remember their answer) There is a part of me that strongly wishes we had a VTL/dedup system, but another part is very happy to be sitting out this round with all the vendor consolidation and product changes. ( Note: I am a FIRM BELIEVER in the worse case scenario! ) Rick ----------------------------------------- The information contained in this message is intended only for the personal and confidential use of the recipient(s) named above. If the reader of this message is not the intended recipient or an agent responsible for delivering it to the intended recipient, you are hereby notified that you have received this document in error and that any review, dissemination, distribution, or copying of this message is strictly prohibited. If you have received this communication in error, please notify us immediately, and delete the original message.
