From: Alan B. <aj...@ms...> - 2008-10-13 13:53:43
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On Mon, 13 Oct 2008, Richerland Medeiros wrote: > How do I use the default compression hardware native of LTO4? > I have 1.4 TB of data and the tape is full when it comes to 900GB. You are using the default compression already, else it would be full at ~795Gb Compression only works on compressable data. Whatever you are putting on the tape has already been compressed. 2:1 compression claims are very optimistic and must be dismissed as marketing puffery. Most of us find that the real average is 1.2:1 on a full backup and higher on incrementals (logfiles are _very_ compressable) The only safe way to estimate how many tapes are needed for any given backup is to use the native capacity of the tape. Compression is a bonus which means you may use fewer, but don't count on it. AB |