On 01/05/11 15:11, Arunav Mandal wrote:
> Very true, in real world data is so different that compression ratio is
> different. Is there any easy way to find out how much data is stored per
> tape?
The Media or Pools view in bat (for one easy way to access it) will show
you the exact amount of data written to any volume, which in the case of
tape hardware compression will be the data amount before compression.
As noted elsewhere, I'm typically seeing around 230GB on an LTO2 tape.
(It should be noted in fairness that by far the majority of the backup
set on my NAS server is already-compressed data such as digital audio
and video.)
The way LTO compression works, the tape drive compresses each block on
the fly, then writes to tape whichever is the *smaller* of the raw or
the compressed block, flagging it accordingly.
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