Hi there
I know that this isn't the place to put a question like this i supose, but i'm geting desperated. I have searched in interbase forums and nothing helped. If anyone can help me i would apreciated.
I'm using HP-UX with a version 3 of interbase wich means i can't split the backup file into... (3 Replies)
Operating system - Solaris 8, Korn shell, xterm
Command
/usr/proc/bin/ptree
outputs the process tree exactly as I want with all detail
However,
/usr/proc/bin/ptree | more
truncates the process descriptions at an 80 character point. If the process tree has marched enough to the right,... (3 Replies)
Hiya all,
Simple question - yet no simple answer im afraid !
Is there a way to execute a shell script (child) which returns one line and get the current (parent) shell to execute the stdout from the child ???
example
child.sh
#!/bin/sh
echo "setenv DISPLAY xxx:03"
parent_prompt>... (5 Replies)
Does anyone know how I can use gzip to zip a large log file on the fly.
My simulation is currently logging a large file that I need for analysis at a later point. However the files are so huge that I may even run out of disk space. The content is mainly text so when compressed the files are... (2 Replies)
Hi,
as part of a script i have a loop that goes though a set of files.
This loop can take some time, so i'd like to show the user that something is happening by showing them the filename being worked on.
I could create a long list of file names in the terminal using echo or print... (0 Replies)
I want to split big files based on a pattern to stdout.
Although csplit works well for me splitting the output into separate files (e.g. xx00, xx01, xx02, ...), the following is not working as expected:
<code>
# assuming pattern occurs less than 100 times
csplit bigfile '%pattern%'... (2 Replies)
Can somebody explain to me why the diff output is not going to stderr?
Yet when I issue a diff from the command line the return code is -ne 1.
I am guessing diff always writes to stdout???
Is there away I can force the difff to write to stderr USING THE CURRENT
template. If possible, I... (5 Replies)
Hi
Is there way to, say, echo a line and make sure it is always displayed on the first line, no matter what is coming out on stdout?
eg:
#!/bin/bash
clear
echo " ...... Internal audit script ......"
tar xvf hugefile.tar
I'd like to have the " Internal audit script " line to be shown... (2 Replies)
Hi,
I have a program set to read in a text file, change certain characters and then print the altered version to the screen but does anyone know how to save the new version as another text file? And, if possible, how to specify the file name, and perhaps location?
Thanks! (2 Replies)
Discussion started by: PerlNutt
2 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)