10 More Discussions You Might Find Interesting
1. Solaris
i need to know the difference between two commands
ps -ef|grep oracle
ps -ef|grep -v grep |grep oracle (1 Reply)
Discussion started by: smazshah
1 Replies
2. Shell Programming and Scripting
Hi all I want to make sure I was understanding this correctly
if a cron job command was
* */20 * * * command
does that mean this command will run every 20 hours?
also what is the difference between the following two?
0,20,40 * * * * command
20 * * * * command
I believe the first... (3 Replies)
Discussion started by: subway69
3 Replies
3. AIX
Hi all,
I'm new in this forum.
I'm looking for the difference between the HACMP commands with the prefix "cl" and "cli".
The first type are under /usr/es/sbin/cluster/sbin directory and the second are under /usr/es/sbin/cluster/cspoc directory.
I know that the first are called HACMP for AIX... (0 Replies)
Discussion started by: peppix
0 Replies
4. Solaris
Looking at the performance hit on my server, does it matter wich command I run?
client # rsh server tar –cf - . | tar –cv –f –
or
server # tar –cf – . | rsh client ‘cd target && tar –xv -f –‘
I think it doesn't really matter because both command strings involve a tar being run on... (4 Replies)
Discussion started by: petervg
4 Replies
5. Shell Programming and Scripting
Hi,
I need to know the difference between this commands:
grep * *search*
grep "*" *search*
As far as i know does the 2nd command search for files which have a name with *search* and greps then all which have chars from a-z in the file content.
But was does the first command??
Best... (1 Reply)
Discussion started by: xus
1 Replies
6. UNIX for Dummies Questions & Answers
Hello! I'm just learning the shell, and I would really like to know how to do this:
Given these 2 commands:
ls -l
ls -le
How can I, with a one-liner, ask the shell to show me visually in the shell, what the difference is between the output of the two commands? They look the same to me... (6 Replies)
Discussion started by: turbofayce
6 Replies
7. Shell Programming and Scripting
Good morning!
What is the difference between:
ssh-keygen -t rsa
and
ssh-keygen -b 2048 -t rsa?
Thanks
Bigben (2 Replies)
Discussion started by: bigben1220
2 Replies
8. UNIX for Dummies Questions & Answers
Hello All, I have a question about the difference between two commands. I am using Korn and was told by the Unix admin that 'nohup <command> &'
equals 'nohup ./<command> &. That there is no difference betwewen the two. Is this true? Also, does the command './<command> &' provide a disconnect... (4 Replies)
Discussion started by: grin1dan
4 Replies
9. Solaris
Hi,
I would like to know what is the difference between executing the mount command in the following ways...
eg:
/usr/sbin/mount -F <something>
AND
mount -F <something>
I mean , just executing the mount command as opposed to specifying the path and then executing it?
... (3 Replies)
Discussion started by: wrapster
3 Replies
10. UNIX for Dummies Questions & Answers
shouldn't they give the same output?
echo `echo \`date\``
is the same as the command date
echo `echo date`
prints the word date
thanks! (3 Replies)
Discussion started by: kfad
3 Replies
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)
