Kopiering af mange filer Emnet er løst

Alle tekniske spørgsmål som ikke hører ind under de andre fora.
Jacob Bahn
Indlæg: 357
Tilmeldt: 25. nov 2008, 11:29

Kopiering af mange filer

Indlægaf Jacob Bahn » 29. sep 2015, 08:08

Når jeg kopierer mange filer til eller fra en ekstern harddisk, falder tempoet støt og det estimerede (og faktiske!) tidsforbrug stiger og stiger. Findes der en forklaring og en vej uden om det?
Mvh Jacob

Jacob Bahn
Indlæg: 357
Tilmeldt: 25. nov 2008, 11:29

Re: Kopiering af mange filer

Indlægaf Jacob Bahn » 29. sep 2015, 10:19

På et tidspunkt sagde den over fire timer. Efter 20-30 minutter var den pludselig nede på 9. Det holdt meget godt. Hvorfor mon det svinger så meget?
Mvh Jacob

zob
Redaktør
Indlæg: 4430
Tilmeldt: 6. jan 2009, 22:01
Geografisk sted: København

Re: Kopiering af mange filer

Indlægaf zob » 29. sep 2015, 12:27

Billede

zob
Redaktør
Indlæg: 4430
Tilmeldt: 6. jan 2009, 22:01
Geografisk sted: København

Re: Kopiering af mange filer  Emnet er løst

Indlægaf zob » 29. sep 2015, 12:33

Lettest forståelige beskrivelse af problemet af Raymond Chen (Microsoft):

Because the copy dialog is just guessing. It can't predict the future, but it is forced to try. And at the very beginning of the copy, when there is very little history to go by, the prediction can be really bad.
Here's an analogy: Suppose somebody tells you, "I am going to count to 100, and you need to give continuous estimates as to when I will be done." They start out, "one, two, three...". You notice they are going at about one number per second, so you estimate 100 seconds. Uh-oh, now they're slowing down. "Four... ... ... five... ... ..." Now you have to change your estimate to maybe 200 seconds. Now they speed up: "six-seven-eight-nine" You have to update your estimate again.

Now somebody who is listening only to your estimates and not the the person counting thinks you are off your rocker. Your estimate went from 100 seconds to 200 seconds to 50 seconds; what's your problem? Why can't you give a good estimate?

File copying is the same thing. The shell knows how many files and how many bytes are going to be copied, but it doesn't know know how fast the hard drive or network or internet is going to be, so it just has to guess. If the copy throughput changes, the estimate needs to change to take the new transfer rate into account.


Kilde: http://blogs.msdn.com/b/oldnewthing/archive/2004/01/06/47937.aspx

PS: Jeg er sikker på at du vil se de største udsving i starten.

Jacob Bahn
Indlæg: 357
Tilmeldt: 25. nov 2008, 11:29

Re: Kopiering af mange filer

Indlægaf Jacob Bahn » 3. okt 2015, 10:00

Tak. Det viste sig jo også, at ca en halv time efter, dialogen sagde over 4 timer, sagde den pludselig 9 minutter - det holdt meget godt
Mvh Jacob

Tilbage til "Tekniske spørgsmål generelt"

Hvem er online

Brugere der læser dette forum: [Bot], [Crawler], Bing [Bot] og 0 gæster