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12 Posts
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701
March 20th, 2022 21:00
Compress backup on tape.
Hi all,
I am taking backup of the file system and database in the Data Domain using the Networker. Then I am sending the backup from the Data domain to the Tape library (Cloning) using the Networker. But I have found that if the backup size is 3TB in the data domain then we are cloning the same size of data in tape (3TB). The tape type is LT07 (native size: 6TB & Compress size is 15TB) but we are not able to use the 15TB.
So my question is, how can we configure compression backup in tape or it is not possible?
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bingo.1
2.4K Posts
1
March 21st, 2022 00:00
AFAIK, there is noway to controlcompressionfrom NW. If you havevendor specific tools, you will most likely use these to control it ... if there is such opton.
Handle compression with care. For example, if you comress the data twice, this may result in even more data. So please be careful.
barry_beckers
393 Posts
0
March 21st, 2022 11:00
What would you expect that the backup to tape dedupes against the DD or what?
All the dedupe you have on a DD is due to the very nature of the DD, nothing else. If you put the backup data on any other medium (even if that other media is also a DD) then any options offered by the other media w/could be used to compress data on its turn, but it will have to do that with the fully hydrated data. The only exception being cloning from DD to DD with Networker, which can use CCR (clone controlled replication) by which only the unique new blocks need to be replicated between the source and target DD's. However that is the only exception. All other clones would be full blown read/write of the backup data.
If cloning to any other medium you are sending the data in it hydrated format to that media. So if you have a 3TB backup, then it will read and write the full 3TB to tape (except maybe using a bit of hardware compression depending on the data in question).
So no, having a DD involved, will not magically also make deduplication available to any data you clone from a DD to tape (or even other disk based solutions). So be prepared to need a lot of tape, for data that dedupes very well on a DD like for example vmware based backups using NW vproxy as those are all regarded as full backups, while DD would apply virtual synthetic full to it, with very high dedupe ratios.
barry_beckers
393 Posts
0
March 21st, 2022 12:00
might have read the original post incorrectly? So it is just regular tape hardware compression that you are after? Not anything you'd really have to configure? It would be applied whenever the data allows for it.
What kind of data are we even talking about?
I can't having had to set anything? It was simply whatever the tape format offered (having dealt with various formats in the past up until LTO). Simply used out-of-the-box really. Some data compressed very good,whereas other data didn't.