Now that I have getch() to work, I have yet another problem. BTW, thank you for answering these questions, I do ask a lot, only because I am eager to know, what is a board used for anyways :)
Ok, he's the problem...
#include iostream.h
#include conio.h
int main()
{
char movement;
... (2 Replies)
Hello
if I like to move file from defined directories system to new directory that not contained any directories system structure .
But I like to create the same file system structure as source directory for example :
I have 2 directories: foo1 and foo2
foo1 have directories and foo2 have... (2 Replies)
hallo, ik heb hier een vraagje. hoeveel gebruikers kunnen er op 1 unix systeem. hopelijk antwoorden golle nu want ik moet da vinde voor school en die leerkracht zaagt. :p
groetjes eu wacht wa was mijne nick ah ja vraagje
groetjes vraagje
ik kan geen engels dus antwoord liever in het... (1 Reply)
Hey my friend was asking me if i knew a way to cout how many different words in a file. I told him no not off hand, but i was thinking about it, and i started to wonder also. I imagine this is probably pretty simple im just missing something, I keep confusing my self with how you would compair and... (16 Replies)
Hi,
Can anyone please explain a little about df command. I have following question:
Following example is showing % used as 4 where as total free blocks are 15.46 out of 16.00 MB blocks.
df -m /test
Filesystem MBblocks Free %Used Iused %Iused ... (5 Replies)
Discussion started by: itsabhi9
5 Replies
LEARN ABOUT DEBIAN
bup-margin
bup-margin(1) General Commands Manual bup-margin(1)NAME
bup-margin - figure out your deduplication safety margin
SYNOPSIS
bup margin [options...]
DESCRIPTION
bup margin iterates through all objects in your bup repository, calculating the largest number of prefix bits shared between any two
entries. This number, n, identifies the longest subset of SHA-1 you could use and still encounter a collision between your object ids.
For example, one system that was tested had a collection of 11 million objects (70 GB), and bup margin returned 45. That means a 46-bit
hash would be sufficient to avoid all collisions among that set of objects; each object in that repository could be uniquely identified by
its first 46 bits.
The number of bits needed seems to increase by about 1 or 2 for every doubling of the number of objects. Since SHA-1 hashes have 160 bits,
that leaves 115 bits of margin. Of course, because SHA-1 hashes are essentially random, it's theoretically possible to use many more bits
with far fewer objects.
If you're paranoid about the possibility of SHA-1 collisions, you can monitor your repository by running bup margin occasionally to see if
you're getting dangerously close to 160 bits.
OPTIONS --predict
Guess the offset into each index file where a particular object will appear, and report the maximum deviation of the correct answer
from the guess. This is potentially useful for tuning an interpolation search algorithm.
--ignore-midx
don't use .midx files, use only .idx files. This is only really useful when used with --predict.
EXAMPLE
$ bup margin
Reading indexes: 100.00% (1612581/1612581), done.
40
40 matching prefix bits
1.94 bits per doubling
120 bits (61.86 doublings) remaining
4.19338e+18 times larger is possible
Everyone on earth could have 625878182 data sets
like yours, all in one repository, and we would
expect 1 object collision.
$ bup margin --predict
PackIdxList: using 1 index.
Reading indexes: 100.00% (1612581/1612581), done.
915 of 1612581 (0.057%)
SEE ALSO bup-midx(1), bup-save(1)BUP
Part of the bup(1) suite.
AUTHORS
Avery Pennarun <apenwarr@gmail.com>.
Bup unknown-bup-margin(1)