on my desktop i am using the kde rotating desktop image option. this rotates images randomly every half hour. now, i would like to write an html file which will have an inline frame with some text, maybe system messages, or my friends live journal thati read alot, or unix.com! however, i dont want... (1 Reply)
I have data file with customer.dat, and this contains the customer names
>cat customer.dat
FirstName1 LastName1
FistName2 LastName1
FistName3 MiddleName3 LastName3
This file can contain areoun 100 customer names.
Regards, (1 Reply)
Hi,
I have an excel file that have a random count of columns/fields and what im trying to do is to only retrieve all the rows under 2 specific field headers.
I can use the usually command for awk which is awk 'print{ $1 $2}' > output.txt, but the location of the 2 specific field headers is... (9 Replies)
I have a directory of files that look like filename 001.ext, filename 002.ext, etc. I'd like to rename the files with unique random numbered names, so that the original filenames are stripped and the files are given a new, random number name. I'm not super new to UNIX, but I don't often use it for... (2 Replies)
I want to create a cron job randomly once a day for my site's registration.
The responsible file for registrations is a config file and I need to change the contents
twice on day (on and off)
I know the way for random cron job for example
*/n * * * * /usr/local/bin/php... (6 Replies)
Hi,
(First post, please be gental!)
I have a java app that I am running on unix (centos)
But it keeps dying randomly. The times seem random from anything between 3 hours and 3 days.
I have a cronjob running to restart it when ever it dies but I would rather this happened less often.
... (2 Replies)
I have a text file with 1000 lines, I want to randomly select 200 lines from it and print them as output. How do I go about doing that? Thanks! (7 Replies)
Hi Tech Guru,
I have a test file as below , which needs some more fields to be populated randomly :
dks3243;12;20130823;1420;25m;0;syt
dks3243;rocy;10
dks3243;kiop;18
sde21p4;77;20151210;8479;7py;9;vfr
sde21p4;temp;67
sfq6i01;12;20120123;3412;4rd;7;jui
sfq6i01;uymk;90
sfq6i01;kiop;51
... (8 Replies)
Hey,
How can i create randomly create time N times.
Suppose i want to create data for a particualr date 5 times...
Mon Jan 19 11:42:50
Mon Jan 19 19:16:40
Mon Jan 19 12:12:33
Mon Jan 19 14:26:27
Mon Jan 19 12:29:53
Mon Jan 19 13:30:31
I want the script to create N times randome... (2 Replies)
Dear Folks
I have one column of 15000 lines and want to select randomly 5000 of them in five different times without replacement. I am aware that command 'shuf' and 'sort -R' could select randomly those lines but I am not sure how could I avoid the replacement of selection line. Does anyone have... (10 Replies)
Discussion started by: sajmar
10 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)