Please help, I am new to shell Programming. I have three files each containg a unique text (key) field (e.g. ABCDEF, XCDUD as shown below), line return followed by some data of which there can be more then one instance. In addition, in some cases there may be no data but only a key field. Please... (18 Replies)
Hi I am going to migrate our datawarehouse system from HP Tru 64 Unix to the Red Hat Linux.
Inside the box, it is running around 40 cron jobs; inside each cron job, it is calling other shell script files, and the shell script files may again call other shell script files or ctl files(for... (1 Reply)
Hi,
Could someone please assist on a quick way of How to extract data from indexed files (ISAM files) maintained in an UNIX(AIX) server.The file data needs to be extracted in flat text file or CSV or excel format .
Usually we have programs in microfocus COBOL to extract data, but would like... (2 Replies)
the sorting is based on name of file,
file size
modification time stamps o f file
it should dislay the output in the following format
"." and ".." enteries should be ignored
please give some idea how to do it (1 Reply)
Hi,
I am new to shell scripting.Please help me on this.I am using solaris 10 OS and shell i am using is
# echo $0
-sh
My requirement is i have source file say makefile.I need to extract files with extensions (.c |.cxx |.h |.hxx |.sc) from the makefile.after doing so i need to check whether... (13 Replies)
I need a script file for backup (zip or tar or gz) of old log files in our unix server (causing the space problem). Could you please help me to create the zip or gz files for each log files in current directory and sub-directories also?
I found one command which is to create gz file for the... (4 Replies)
Hi,
Very good wishes to all!
Please help to provide the shell script for generating the record counts in filed wise from the .csv file
My question:
Source file:
Field1 Field2 Field3
abc 12f sLm
1234 hjd 12d
Hyd 34
Chn
My target file should generate the .csv file with the... (14 Replies)
i use the split command to split a one terabyte backup file into 10 chunks of 100 GB each. The files are split one after the other. While the files is being split, I will like to scp the files one after the other as soon as the previous one completes, from server A to Server B. Then on server B ,... (2 Replies)
Discussion started by: malaika
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)