We just purchased a MOD30 disk array strage system.
We have 15 drives and 2 hot spares.
We're running a database app with 8 data sets.
I'm trying to get the best i/o speed out of my disk configuration.
Right now I have 3 raid5 arrays setup. This seems to offer the same performance as having the... (1 Reply)
When setting a variable, how would I go about making each result a new line?
A very simple example would be:
theFolders=`(ls -l /)`
echo $theFolders
This gives me all the folders as one variable and I need to be able to use each as its own variable. I'm sure I have to make this into an... (2 Replies)
Hi all,
I have a question does anyone know if it is possible to push or pop an array in the ksh environment? Could anyone give me a hint, because I am trying to merge 2 server files together and there are some names in the server is not proper anymore.
Thank you in advance. (4 Replies)
suppose my @{$data1{$callid}}; cotains
one two three
three five six
one two three
of random patterns but each item is separated by white space or tab,
Below code extract and get rid of the whitespace perfectly so that it shows now like this
onetwothree
threefivesix... (2 Replies)
I need to implement the following logic and need some expert help from UNIX community.
These are the steps in my Shell script.
1. Analyze a file.
2. Extract all the ID's in that file.
3. Use the ID's from #2 to run another filter on the file.
I've implemented # 1 and 2 using... (3 Replies)
Greetings,
DISCLAIMER: My shell scripting is rusty so my question may be borderline stupid. You've been warned.
I need to create a script that a) lists the content of zip files in a directory and b) sends out an `exception` report. My ZIP files contain a control file (for load check). I want... (2 Replies)
Im new to C programming and am having trouble understanding the output of this code
int array={4,5,8,9,8,1,0,1,9,3};
int *array_ptr;
int main()
{
array_ptr=array;
while((*array_ptr) != 0)
array_ptr++;;
printf("%d\n", array_ptr - array);
return(0);
}
the output is 6 but I... (2 Replies)
Hi,
I am trying to do something similar to the for loop example from KSH For Loop Array: Iterate Through Array Values
$: cat y.ksh
#!/bin/ksh
# set array called nameservers
set -A nameservers 192.168.1.1 192.168.1.5 202.54.1.5
# print all name servers
for i in ${nameservers}
do
... (3 Replies)
Inside a zsh function, I create a local array with local -a arrayname and a local associative array with local -A arrayname.
I also can create an array using set, like this:
set -A arrayname value1 value2 value3In this form, I can not explicitly declare that an array is associative or... (2 Replies)
I am trying to assign indexes to an associative array in a for loop but I have to use an eval command to make it work, this doesn't seem correct I don't have to do this with regular arrays
For example, the following assignment fails without the eval command:
#! /bin/bash
read -d "\0" -a... (19 Replies)
Discussion started by: Riker1204
19 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)