Hi,
I'm confused about how the DD Boost plug-in works. Can anyone help explain?
We are setting up a new backup infrastructure with Netbackup 7.5 on two sites with mixed Windows and Unix clients writing to Data Domain boxes which replicate via SLP across the wan.
We have a capacity license and large servers >50gb data are being installed as media servers with the DD Boost OST plugin. These servers will only back themselves up - other media servers will be promiscuous and pickup other clients at random. At this point each large server will probably need its own storage unit so it can only back itself up.
1) My understanding is that the DD boost plugin will dedupe at source, so that after an initial full backup subsequent backups will be much smaller. How does it do that? Does it record all the blocks of data sent onto a list, then not send any matching blocks in future backups? Or does the plugin communicate directly with the DataDomain storage boxes?
2) If a server has Netbackup media server and the DD Boost plugin installed, but is backed up by a second media server (which may or may not have the DD Boost plugin installed), will that backup be deduped at source or not? In other words, will the first media server dedupe its data then send it on to the second media server to then be sent to the DD storage box?
3) Forgetting dedupe at source for the moment, as I understand things once an original full backup is written to the DataDomain box then future backups of the same client are radically 'squashed' after they arrive - only blocks of data that aren't already present in the original full backup are retained. (Kind of like full and differential or incremental backups work on a file level). But what happens if you eventually write your original full backup (written for example on 1st October) off to tape and its retention period expires? All the subsequent backups rely on the 1st October template for their integrity, but if the original is no longer present on the DD box then they can never be 'reinflated' as full backups in their own right. :-O
Is the data Domain box a lot cleverer than this - does it continually keep the blocks it needs and discard those it doesn't, so even if you wrote to tape and deleted the 1st October backup those blocks that were still needed for subsequent backups would be retained?
Thanks!
Confused of Hampshire