09-08-2015 12:53 AM
Hi All,
I need to archive off about 30TB of data from a storage subsystem to LTO5 tape(s). The data is in the form of uncompressed files on a Windows server (documents, images, etc).
I don't need to archive it all off, but I do want to archive most of it which allows me to make best use of a bunch of LTO5's, Ie, using the full capacity of 5 LTO tapes rather than 5 LTO tapes and a then a little bit more on a 6th tape.
Is there a way I can determine how much of this uncompressed data will fit onto an LTO5 after compression etc as I really don't want to be wasting tapes....
Thanks :)
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09-08-2015 01:00 AM
Compression is subjective and you will never get 2:1. If anything, work on a real-world compression ratio of 1.1:1 --> 1.4:1, and I personally would work on something inbetween.
Thanks!
09-08-2015 01:00 AM
Compression is subjective and you will never get 2:1. If anything, work on a real-world compression ratio of 1.1:1 --> 1.4:1, and I personally would work on something inbetween.
Thanks!
09-08-2015 01:23 AM
09-08-2015 12:54 PM
Craig is spot on here. Size for about 1.1:1-1.4:1, which is a more common compression rate.
09-08-2015 06:25 PM
These ratios are only applicable for uncompressed data.
09-08-2015 11:15 PM
...I suspect the data here is a mix of images and documents etc, so compression is going to be subjective. Some files MAY decompress, the rest should, but the ratio can't be accurately estimated.
09-14-2015 03:40 AM
So if I have an LTO5 tape which is 1.5TB native, 3TB compressed, that assumes 2:1 ratio right?
But what you are saying is you will never reach that ratio, so let's say a realistic ratio would be 1.2:1.
My uncompressed data is 3.48TB, divide this by the compressed tape size (3TB), this gives me 1.16:1, does this sound right? If so then this *should* fit onto an LTO5 right?
Thanks for all your helps so far :)
09-14-2015 03:47 AM