i tried to ask about this earlier, but didn't explain well enough. From a script, i issue the following:
echo `pgp --encrypt filename --recipient public-key`
The result is perfect. The encrypted file is in the directory just as if i'd issued the pgp command from the command line.
However,... (0 Replies)
Hi,
We have umask 022 in /etc/profile for security reasons.
But I want have some other umask for selected users. how to achieve this?
Regards (3 Replies)
I am running Linux 2.6.20 on i686 architecture.
I want to be able to masquerade different hosts on my LAN to different external interfaces. Specifically, I want one specific host to masquerade through a vpn tunnel while the other hosts simply masquerade over the regular ISP interface. I only... (4 Replies)
hi all
from below text
"abcd,SYS_12345,xyz,PQR, ,"
I want to print only
"abcd,SYS,xyz,PQR, ,"
i.e. taking only first three 3 chars from 2 string of comma separated file
thanks (4 Replies)
Hello,
I have been using the command below for file manipulation.
while read A B; do grep $f1; done < f2 > f3
So, if a certain string is found in f2 (for ex; DOG243435) and it is also present in f1, then print that string plus the contents of the line in which it was found onto f3.
... (6 Replies)
Hi all
:wall:
Can anyone advise how do I use ls to do a selective amd sorted listing of file that I want to have as below?
Am looking for files that are named as log_<nnnn>.txt, where <nnnn> are numeric, i.e. I want to have a listing sorted from the newest to the oldest of files that... (7 Replies)
I have to grep out only email address from a column. It has characters appended and prepended
F=<sss1@domain.com>
<sss2@domain.com>
(sss3@domain.com)
<sss4@domain.com>
Whatever added before and after email, I should be able to grep out only emails. (9 Replies)
I have a text file in this format.
Group: AAA
Notes: IP : 11.11.11.11
#User xxxxxxxxx
#Password aaaaaaaaaaaaaaaa
Group: AAA
Notes: IP : 11.11.11.22
#User yyyyyyyyyyyyy
#Password bbbbbbbbbbbbb (8 Replies)
i have a large sequence of format
sat_1_g3_g_0_8540 . A 1 15501 . . . ID=sat_1_g3_g_0_8540;parentName=sat_1_g3_g_0_8540;Al=sat_1_g2_g_0_8540;
sat_1_g3_g_2_8510 . C 1 25501 . . . ... (11 Replies)
I have the following contents in a file
---- CRITICAL: altered for /usr/bin/bin1 ---- OK: /usr/sbin/bin2 result fine ---- OK: /usr/sbin/bin3 result fine ---- CRITICAL: altered for /usr/bin/bin4 ---- OK: /usr/bin/bin5 result fine ---- OK: /usr/bin/bin6 result fine ---- CRITICAL: altered for... (9 Replies)
Discussion started by: anil510
9 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)