Just a super quick question:
how do you put a link in your php code.
I want to make a link to something in /tmp directory.
i.e. how do you put a href into php, I think it's done a bit differently.
thanks
john (1 Reply)
Hi, I am new to UNIX, and am learning from this tutorial : http://www.ee.surrey.ac.uk/Teaching/Unix/index.html
It keeps telling me to files downloaded from the internet (like .txt files) to the directory, and I dont know how to.
How do I add .txt files to my directory? Thanks. (6 Replies)
Hi,
At best I'm a junior admin with a big problem.
My developers have got my root password and mgmt insists they need it.
I can't even change it when people knowing it leave.
I'm certain they've hardcoded it into routines. I've searched my servers and grepped everything & can't find it.
... (5 Replies)
I'm in .profile. I want to export a directory ( export MY_TOOL_HOME=/tools/my tool". Unfortunately for me, the directory I want to export to has a space in its name. So when I try to cd $MY_TOOL_HOME, i get a No such file or directory at the command line... thanks for the help (4 Replies)
When I have a file like this:
0084AF aj-123-a NAME Ajay NAME Kumar Engineer
015ED6 ck-345-c
020B25 ef-456-e
027458 pq-890-p NAME Peter NAME Salob Doctor
0318F0 xy-123-x NAME Xavier Arul NAME Yesu Supervisor
0344CA de-456-d
where - The first NAME is followed by... (6 Replies)
Hi guys
Quick question
Im creating an FTP server and im chrooting each user to there home directory blah blah. Ive also setup scponly so there locked etc.
Im a novice at unix and have just reaslised the primary group of scponly is the username of one of the ftp users... which im sure... (1 Reply)
I need to speed up this process. I would like for this script to spawn a sub-process for each line it reads and move on to the next without waiting for the data to be returned.
I know with a large list this can be dangerous and eat system resources. However I use this script only when I get a... (7 Replies)
Hello,
I have a quick reference question:
I have a very long, but fairly straigtforward script written in c-shell. I was wondering if it is possible to call this script from bash (for ex. having a function in bash script which calls the c-shell script when necessary), and if so, are there any... (1 Reply)
Discussion started by: lapiduslost
1 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)