I'm trying to make a backup of a directory tree on Solaris 8. I'm doing this with my own ID, not root. The problem I am running into is when I extract the archive, all files are owned by me and the group is my default group. The man page lists this as the default behavior when executed by a... (1 Reply)
Hi all,
I've been trying to get this to work for ages to no avail. I've searched this site and googled but cannot find a satisfactory answer.
I've got a while loop, like this
while read line
do
echo "$line"
done < file_name
Now, my problem is that most of the lines in the file... (3 Replies)
I'm trying to search all .odt files in a directory for a string in the text of the file.
I've found a bash script that works, except that it can't handle whitespace in the filenames.
#!/bin/bash
if ; then
echo "Usage: searchodt searchterm"
exit 1
fi
for file in $(ls *.odt); do
... (4 Replies)
Hi,
I have a for loop which iterates over a list of strings, separated by whitespace:
$ list="1 2 3"
$ for i in $list; do echo $i; done
1
2
3
I now want to introduce some strings containing whitespace themselves ... This is straightforward if I directly iterate over the list:
$ for... (4 Replies)
I'm trying to get a number of old disks on HP-UX 10.2 copied over to a new Debian machine which has a NAS on it.
The HP does not have rsync, but does have scp. Scp unfortunately does not always preserve permissions, and does not save links which were on the disk.
Apparently rsync has a flag... (3 Replies)
Hi
Following is an example line.
echo "192.22.22.22 \"33dffwef\" 200 300 dsdsd" | sed "s:\(\ *\ \):\1:"
I want it's output to be
200
However this is not the case. Can you tell me how to do it? I don't want to use AWK for this. Secondly, how can i fetch just 300? Should I use "\2"... (3 Replies)
Hi guys,
I'm trying to unzip a file and rename it to another while preserving the original timestamp:
$ cat file.dat.gz | gzip -d > newfile.dat
My goal is to assign the file.dat.gz timestamp to newfile.dat.
I cannot use gunzip, due to various checks done with wget. Basically, I have to... (1 Reply)
Below is the issue I am having.
I have a few variables which have certain values in them like
var1=23
var2=46
var3=78 etc...
I want to save these values with the help of a for loop in a single variable so that I can use it later,beacuse a few lines down the script, some of these... (3 Replies)
Hi I am running this shell script .But some how the flag value is getting reset to 0 .could you please help .I'm pasting the output of the script also for your reference.
#!/usr/bin/sh
# Shell script to monitor or watch the disk space
# It will send an email to $ADMIN, if the (free... (5 Replies)
I am trying to do in a single line to take a list of paths separated by whitespace and then loop thru all the paths that were wrote but my regex is not working,
I have
echo {3} | sed 's/ //g' | while read EACHFILE
do
.....
But for some reason is only taking always the first path that I... (7 Replies)
Discussion started by: jorgejac
7 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)