Timeline for Move data with compression
Current License: CC BY-SA 3.0
12 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Apr 17, 2014 at 13:40 | comment | added | Daniel B | The compression algorithm. It would have to run to completion to tell the result size—which, naturally, takes ages. And if it were to fit, you'd have to run it again. This is only a solution when your storage is over 2 times slower than the compression. You know, 56K modem speed and the like. | |
| Apr 17, 2014 at 13:38 | comment | added | yosh m | If you know the nature of the data you can guesstimate the compression. As others have noted, some data won't compress at all (e.g., jpg, mp3, etc.) since it's already compressed while other data (e.g., text files) can compress up to 90% (or more). For a perfect prediction, it is true - you (or rather some program) must process all the data. What is your goal? To figure out how big a spare disk you must buy to save your data during formatting? I have a better suggestion: buy another 2TB drive and let it be your backup drive moving forward, too (not just while you format your drive). | |
| Apr 17, 2014 at 12:10 | comment | added | mrgloom | @DanielB what algorithm? how I can test it? | |
| Apr 17, 2014 at 11:45 | comment | added | Daniel B | Sure, you could discard all compressed data and only keep the size. This would, however, still require the algorithm to process all data. | |
| Apr 17, 2014 at 8:22 | comment | added | bonob | It also depends on the kind of data you want to compress. If it's all mpeg, jpeg, mp3, you won't gain anything from compression. | |
| Apr 17, 2014 at 7:40 | comment | added | ek9 | Because this is how compression works. You cannot tell the size until you go through the file and try to compress it. | |
| Apr 17, 2014 at 7:38 | answer | added | Peter Lamby | timeline score: 1 | |
| Apr 17, 2014 at 7:36 | comment | added | mrgloom | @DanielB why not? What if algorithm pass through data and calc size of resulting archive?If it needed for "dictionary"(or something) it may use some "buffer" on disk which size is previously predifined and deleted after calculation. | |
| Apr 17, 2014 at 7:31 | comment | added | mrgloom | @yoshm I want to format full disk. The question is that I have X Gb of data I want to know how large "spare" disk I need to backup it. | |
| Apr 17, 2014 at 7:29 | comment | added | Daniel B | There is no such thing as a predictable compression ratio. Deal with it. | |
| Apr 17, 2014 at 7:19 | comment | added | yosh m | How much data is on the disk you want to format? How much data are you trying to save? How big is the "spare" disk that you have where you want to store the data while formatting? | |
| Apr 17, 2014 at 7:02 | history | asked | mrgloom | CC BY-SA 3.0 |